McG's BIOL 1404

Final Thoughts

2009-02-24T19:41:00.000-08:00

Many of you have worked hard this semester and have learned a great deal of biology. You should be congratulated for that. You still have a long way to go, so I encourage you to keep working hard. If you are frustrated by your performance in the course thus far don't be disappointed. You have two more midterms, lab, and the final exam to raise your grade so keep at it.

Thanks for making this a great semester. I have enjoyed getting to know some of you a little bit this semester and I look forward to getting to know more of you in the future. I would like to say that I will miss you all, but I am ready for a break! Have a great semester and keep in touch.

See you at the final,

Mark McG

Answer Key for Second Midterm

2009-02-24T19:28:00.000-08:00

The BAC will meet Wednesday at noon in room 204 in McClellan Hall. Please attend if you can, but don't miss a class to come to the BAC meeting.

Multiple Choice Answers

Form 1 and Form 2

1. a
2. b
3. b
4. a or e
5. d
6. c
7. d
8. b
9. a
10. b
11. d
12. a
13. d
14. b
15. b
16. c
17. d
18. a
19. b
20. e
21. b
22. c
23. a
24. d
25. d
26. a
27. d
28. c
29. b
30. a

Essay Questions

Photosynthesis Question

The rate of photosynthesis can be limited directly, or indirectly, by a variety of environmental factors. Agriculture provides us food and fiber and is a major component of the economy in many parts of the world. Farmers attempt to increase the production of their crops by fertilizing and irrigating.
Discuss how fertilization and irrigation can increase agricultural production by increasing rates of photosynthesis. An excellent answer will indicate how these activities affect the physiology of plants in a way that increases the rate of photosynthesis.

The rate of photosynthesis can be limited by a variety of environmental factors including temperature, light level, carbon dioxide, soil fertility, and water availability. Some of these factors (e.g., soil fertility and soil moisture level) can be manipulated by farmers in a way that can increase photosynthetic rates production whereas other factors (e.g., temperature and atmospheric carbon dioxide concentration) are harder to manipulate on a large scale. Thus, most large scale agriculture involves increasing soil nutrients by adding fertilizers and increasing soil moisture availability by irrigation.

Water can indirectly regulate the rate of photosynthesis. Irrigating crops increases the soil moisture content. When plants are water stressed they respond by closing their stomata which blocks carbon dioxide from entering the leaf by diffusion. Carbon dioxide is required in the light independent reactions of photosynthesis. The ultimate purpose of the light independent reactions is to use energy from ATP and NADPH to convert carbon dioxide to glucose which contains chemical energy stored in its chemical bonds. Specifically, carbon dioxide is involved in the following reaction-
CO2 + RuBP  PGA
Irrigating crops increases the soil moisture content which allows plants to keep their stomata open longer which allows them to take up carbon dioxide for a longer period of time which allows photosynthesis to occur longer.

Fertilizing can add a number of potentially limiting resources to the soil. An important nutrient in all fertilizers is nitrogen. Because nitrogen is an important element in amino acids, increasing soil nitrogen content can increase the rate of nitrogen uptake which allows plants to make more proteins. By far the most protein in plants is RuBP carboxylase, the enzyme that catalyzes the reaction between carbon dioxide and RuBP. Fertilizing with nitrogen increases the amount of RuBP carboxylase in the plant which speeds up carbon fixation and allows more carbon to be produced in the Calvin Cycle.

Life Cycle Question

Diagram the life cycle of a fern. Discuss the characteristics of ferns that makes them advanced relative to the mosses and primitive relative to the gymnosperms. Be sure to discuss the evolutionary advantage of the advanced traits relative to the primitive traits.
(I am sorry that this doesn't look right when it is posted)

zygote (2N) ==> sporophyte (2N) ==> sporangia (2n)
fertilization
meiosis
archegonia => (egg N) <== gametophyte <== spores
angtheridia=> (sperm N) mitosis

Ferns appeared at an intermediate step of the evolution of plants. Thus, they are advanced relative to the bryophytes but primitive relative to the gymnosperms. Ferns are considered to be advanced relative to the bryophytes because they are diploid dominant and have a vascular system and they are considered to be primitive to the gymnosperms because they are homosporous rather than heterosporous and they reproduce by spores rather than seeds.

Diploid dominance is advantageous relative to haploid dominance because individuals are not as adversely affected by lethal alleles. If an organism is haploid then they will die if they get a lethal mutation. However, if that lethal mutation is recessive, then that allele can be masked in the heterozygote state in a diploid organisms. Thus, dipoloid dominant species should have higher survival levels than homozygous dominant species.

The evolution of the vascular system (xylem, phloem, roots, stems, leaves) which occurred for the first time in ferns is a major adaptation for terrestrial plants. Plants with a vascular system produce true roots that can take up water and nutrients from the soil. They have xylem, the tissues that carry water and nutrients from the roots to the leaves, and phloem that carries sugar around the plant. Having a vascular system is a huge advantage because it allows plants to achieve a much larger size and allows them to inhabit more arid regions.

Heterospory, the production of two types of spores to produce two types of gametophytes, is an advantage over homospory, the production of one type of spore to produce one type of gametophyte because heterosporous plants no longer have to rely on swimming sperm. Thus, heterosporous plants have the potential to live in environments that are arid year around.

Reproducing by seeds is a major advantage relative to reproducing by spores because an individual seed has a much larger probability of survival. Seeds contain an embryo, seed coat and nutritive tissues. The resources held in the seed are used to nourish the germinating seedling until it is has established its roots and leaves well enough to collect its own food.

Plant Diversity- The Gymnosperms and Angiosperms

2009-02-19T13:24:00.000-08:00

Gymosperms and angiosperms are the "seed plants".

Gymnosperms

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- defne and contrast homospory and heterospory
- discuss the evolutionary advantage of heterosporty over homospory
- identify the parts of a seed and discuss why reproducing by seeds is an advantaged compared to reproducing by spores
- discuss the life cycle of a pine
- discuss the characteristics of pines that are advanced relative to the ferns and those that are primitive relative to the angiosperms

Angiosperms

Expected Learning Outcomes

At the end of the course a fully engaged student should be able to

- discuss the parts of a flower
- discuss the evolutionary advantage of reproducing by flowers rather than by cones
- discuss the life cycle of an angiosperm
- discuss the characteristics of angiosperms that are advanced relative to the pines and those that are primitive relative to the angiosperms
- discuss why angiosperms are the most successful of all plant groups

Plant Diversity- Ferns

2009-02-19T06:29:00.001-08:00

Ferns are examples of the first vascular plants.

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- discuss the components of the vascular system
- discuss the advantage of a having a vascular system
- diagram the life cycle of a fern
- discuss the morphological and physiological characteristics of ferns
- discuss the characteristics of ferns that makes them considered to be advanced relative to mosses but primitive relative to the gumnosperms
- discuss how the morphological and life history characteristics limits their size and geographic distrubution

Plant Diversity- Algae to Mosses

2009-02-18T11:15:00.000-08:00

As I mentioned in class, plants are interesting to me because the are so different than we are. At first these differences will cause unfamiliarity but eventually you will not be so bogged down by learning new vocabulary and you will hopefully come to realize that plants are more interesting than you might have thought (and besides, no plants means no dorritos, french fries, or beer?).

Further Viewing

1) Here is the slideshow that I will use in class for the final three lectures.

http://www.slideshare.net/secret/DBv71wnKTH1YBN

2) Here is a powerpoint presentation from a group called "world of teaching" that covers plant diversity? There are many "quiz questions" that should be helpful to look at.

http://www.worldofteaching.com/powerpoints/biology/Plant%20Divisions.ppt

Primitive Plants

Expected Learning Outcomes

A the end of this course a fully engaged student should be able to

- functionally define a plant
- discuss the characteristics of a primitive plant such as Chlamydomonas
- diagram a life cycle of a human
- diagram the life cycle of Chlamydomonas
- distinguish between oogamy and isogamy
- discuss the evolutionary advantage of multicellularity, diploid dominance, and oogamy

Transition to Land

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- discuss the problems plants face when moving to the land
- discuss the characteristics of the ancestor of land plants
- diagram the life cycle of a moss
- discuss the morphological and physiological characteristics of mosses
- discuss the characteristics of mosses that makes them considered to be advanced relative to primitive plants but primitive relative to the ferns
- discuss how the morphological and life history characteristics of mosses limits their growth and geographic distribution

Cellular Respiration

2009-02-17T12:22:00.000-08:00

Cellular respiration converts chemical energy in glucos to chemical energy in ATP which is the ultimate source of energy used to do "biological work".

Glycolysis

1) Glycolysis animation

http://www.youtube.com/watch?v=7hiwSCUoSZY

2) Another Glycolysis animation- this one goes into a little more chemical detail so it might be useful if you are intersted in knowing more about the chemistry

http://www.youtube.com/watch?v=x-stLxqPt6E

Anaerobic Respiration

Alcohol Fermentation and Lactic Acid Fermentation

Further Reading

Alcohol Fermentation- http://www.tempeh.info/fermentation/alcohol-fermentation.php

Lactic Acid Fermentation- http://www.tempeh.info/fermentation/lactic-acid-fermentation.php

Further Viewing

http://www.youtube.com/watch?v=y_k8xLrBUfg

Aerobic Respiration

1) Aerobic Respiration

http://www.youtube.com/watch?v=iXmw3fR8fh0

2) Krebs Cycle

http://www.youtube.com/watch?v=aCypoN3X7KQ&feature=related

3) Electron Transfer Chain

http://www.teachertube.com/view_video.php?viewkey=a67b8fcdafb25c122359

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- discus glycolysis, anaerobic respiration, alcohol fermentation, lactic acid fermentation, aerobic respiration, the Kreb's Cycle, and electron transport
- compare and contrast aerobic respiration with anaerobic respiration
- discus why the breakdown of glucose to produce ATP is so much more efficient when oxygen is present
- describe where in the cell the different parts of cellular respiration take place

Factors That Limit the Rate of Photosynthesis

2009-02-17T11:52:00.001-08:00

The rate of photosynthesis can be limited by a variety of environmental factors including

1) light
2) concentration of carbon dioxide
3) water
4) soil nutrients

Which factor most limits photosynthesis varies between environments.

Light- Can directly limit the rate of photosythesis by limiting the rate at which ATP and NADPH are produced

Carbon dioxide- can directly limit the rate of photosynthesis by limiting the rate at which the Calvin Cyle takes place

Water- can indirectly limit the rate of photosynthesis. When plants are water stressed they close their stomata (long before the concentration of water in the cell becomes too low for water to supply electrons to P680). Thus, the rate of photosynthesis is water stressed plants is directly limited by the amount of carbon dioxide in the leaf.

Soil Nutrients- Sometimes the rate limiting step in photosynthesis is the rate at which carbon dioxide + RuBP ==> PGA. This reaction is catalyzed by the enzyme RuBP carboxylase. Increasing the amount of RuBP carboxlyase in the cell can increase the rate at which this reaction occurs. Fertilizing plants with nitrogen will increase the amount of RuBP Carboxylase produced by the plant.

Expected Learning Outcomes

By the end of this class a fully engaged student should be able to

- discuss the factors that can directly or indirectly limit the rates of photosynthesis
- discuss how the most limiting factors should vary between environments
- discuss how the activities of farmers such as irrigation and fertilization can increase photosynthetic rates
- interpret the graph at the top of the post (irradiance measures light intensity and the three lines represent different concentrations of carbon dioxide)
- explain what why the graph shows that shape

Why Are Plants Green? or Why Aren't Plant Black?

2009-02-17T06:45:00.000-08:00

If I was hired as an engineer to design a machine whose job was to convert light energy into chemical energy I probably would not choose to use a green pigment. Instead, I would choose to use a black pigment because black pigments would absorb more energy because they would absorb all wavelengths of light. If you look at a field of plants you will notice that they are green (OK this doesn't work too well around Lubbock in the winter)and we have learned that chlorophyll, a green pigment, is the dominant photosynthetic pigment. What is going on?

Here is one theory about why chlorophyll is the dominant photosynthetic pigment in plants today. Early on there were photosynthetic bacteria with purple pigments (purple is a combination of red and violet). These aquatic bacteria had a very simple sort of cyclic electron flow that was able to convert light energy into energy in ATP (they didn't have non-cyclic flow or the Calvin Cycle).

Origin of chlorophyll- The purple pigment absorbed all wavelengths of light except for the reds and violets. Thus, any bacteria using purple pigments that lived deeper in the water than the purple bacteria on the surface would have no light to use because it had all been absorbed by the surface bacteris (exploitative competition). Because red and violet wavelengths pass through to deeper water, bacteria that contained a pigment that was able to absorb these wavelengths would be able to coexist with the purple bacteria. This was the origin of chlorophyll.

Competition purple and green photosynthetic pigments. Over time there was competition between organisms with purple photosynthetic pigments and green photosynthetic pigments. Obviously, the green photosynthetic pigments won this competition because chlorophyll is the dominant photosynthetic pigment today (there are still examples of photosynthetic bacteria with purple pigments, but they are limited to very harsh environments). Interestingly, chlorophyll came to dominate, not because it was a better at absorbing light energy, but rather because the cyclic flow machinery associated with chlorophyll was more efficient at producing ATP than the machinery associated with the purple pigment was. Thus, it is an evolutionary accident that modern plants are green.

Black Plants

It would be possible for modern plants to be black if they had enough accessory pigments to allow them to absorb all wavelengths of light. In fact, some red algae that live deep below the surface where light levels are low are basically black. Because the amount of light is not the factor that limits the rate of photosynthesis in most terrestrial plants, it is not worth the cost of producing extra accessory pigments. However, deep in the ocean where light levels are low, plants benefit from being able to absorb all wavelengths of light so deep marine algae have invested in extra accessory pigments.

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- discuss why terrestrial plants to not invest in the accessory pigments required to make them black

Carbon Fixation

2009-02-17T06:35:00.000-08:00

Technically, arbon fixation is defined as the first chemical reaction that incorporates carbon dioxide into an organic molecule (a molecule with more than one carbon atom).

In C3 photosynthesis the following step is considered to be carbon fixation-

carbon dioxide + RuBP ==> PGA

In CAM photosynthesis the following is considered to be carbon fixation-

carbon dioxide ===> malate

Note: CAM plants also have the reaction- carbon dioxide + RuBP ===> PGA, but in this case this step is not considered to be carbon fixation.

Sometimes people will loosely use the term carbon fixation to mean the production of glucose by photosynthesis. Be sure that you are aware of how different authors are using the term and you should attempt to use the term as precisely as possible in your own work.

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- define carbon fixation
- identify carbon fixation in C3 and CAM photosynthesis

CAM Photosynthesis

2009-02-17T06:23:00.001-08:00

CAM photosynthesis is an alternative mode of photosynthesis found in some plants adapted to living in desert environments. CAM plants are able to separate the timing of carbon uptake from the timing of the use of carbon dioxide in the Calvin Cycle which reduces the water loss of these plants.

Critical Point- All of the nuts and bolts of photosynthesis (e.g., photosystems, light dependent reactions, and Calvin Cycle) take place the same in C3 and CAM plants.

Epected Learning Outcomes

By the end of this course a fully engaged student should be able to

- discus the timing of carbon uptake and glucose production in CAM plants
- discuss the advantages and disadvantages of CAM photosynthesis
- explain why CAM photosynthesis is limited to plants growing in arid environments
- compare and contrast photosynthesis if C3 and CAM plants

Leaf Structure

2009-02-17T06:16:00.000-08:00

In most plants, leaves are the major sites of photosynthesis. Thus, we can think of leaves as "photosynthesis machines" and use our knowledge of natural selection to try to understand aspects of leaf structure.

Further Reading

http://micro.magnet.fsu.edu/cells/leaftissue/leaftissue.html

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- discuss important differences between animals and plants in gas uptake
- diagram the cross section of a leaf
- explain the adaptive basis of leaf structure

Global Carbon Cycle Revisited

2009-02-15T10:35:00.000-08:00

Here is some more information that I would like you to know about the global carbon cycle

Mauna Loa Curve

The best data that we have examining is from Mauana Loa in Hawaii (see Mauna Loa Curve- http://www.eoearth.org/article/Mauna_Loa_curve). This curve shows two things. First, that the concentration of carbon dioxide in the atmosphere has indeed increased over time. Second, that there is seasonal variation in the concentration of carbon dioxide in the environment. Carbon dioxide is most abundant in the atmosphere in the North American winter and lowest in the North American summer. This pattern is caused by seasonal variation in the amount of photosynthesis. In the summer, when photosynthetic rates are the highest, carbon dioxide is removed from the atmosphere at a high rate which reduces the amount of carbon in the atmosphere. Because there is more land mass in the Northern Hemispere and most photosynthesis happens on land, the global pattern is determined by seasons in the Northern Hemispere (this is truly a global cycle, carbon dioxide move so quickly though the environment that the conentration is virtually the same all over the world)

Expected Learning Outcomes

By the the of this class a fully engaged student should be able to

- diagram how carbon dioxide concentration in the atmosphere varies seasonall.
- discuss the causes of this pattern

What is Happening to the Rate Carbon Dioxide is Being Added to the Atmosphere?

Here is an article from the Associated Press entitled- Climate Warming Gasses Rising Faster than Expected that was published yesterday. Chris Field, one of the scientists quoted in this article, was one of my professors at University of Utah.

CHICAGO (AP) -- Despite widespread concern over global warming, humans are adding carbon to the atmosphere even faster than in the 1990s, researchers warned Saturday. Carbon dioxide and other gases added to the air by industrial and other activities have been blamed for rising temperatures, increasing worries about possible major changes in weather and climate.

Carbon emissions have been growing at 3.5 percent per year since 2000, up sharply from the 0.9 percent per year in the 1990s, Christopher Field of the Carnegie Institution for Science told the annual meeting of the American Association for the Advancement of Science.

''It is now outside the entire envelope of possibilities'' considered in the 2007 report of the International Panel on Climate Change, he said. The IPCC and former vice president Al Gore received the Nobel Prize for drawing attention to the dangers of climate change.

The largest factor in this increase is the widespread adoption of coal as an energy source, Field said, ''and without aggressive attention societies will continue to focus on the energy sources that are cheapest, and that means coal.''

Past projections for declines in the emissions of greenhouse gases were too optimistic, he added. No part of the world had a decline in emissions from 2000 to 2008.

Anny Cazenave of France's National Center for Space Studies told the meeting that improved satellite measurements show that sea levels are rising faster than had been expected. Rising oceans can pose a threat to low level areas such as South Florida, New York and other coastal areas as the ocean warms and expands and as water is added from melting ice sheets.

And the rise is uneven, with the fastest rising areas at about 1 centimeter -- 0.39 inch -- per year in parts of the North Atlantic, western Pacific and the Southern Ocean surrounding Antarctica, she said.

Also, highly promoted efforts to curb carbon emissions through the use of biofuels may even backfire, other researchers said. Demand for biologically based fuels has led to the growing of more corn in the United States, but that means fields were switched from soybeans to corn, explained Michael Coe of the Woods Hole Research Center. But there was no decline in the demand for soy, he said, meaning other countries, such as Brazil, increased their soy crops to make up for the deficit.
In turn, Brazil created more soy fields by destroying tropical forests, which tend to soak up carbon dioxide. Instead the forests were burned, releasing the gasses into the air. The increased emissions from Brazil swamp any declines recorded by the United States, he said.

Holly Gibbs of Stanford University said that if crops like sugar and oil palm are planted after tropical forests are burned, the extra carbon released may be balanced by lower emissions from biofuel in 40 to 120 years, but for crops such as corn and cassava it can take hundreds of years to break equal.

''If we run our cars on biofuels produced in the tropics, chances will be good that we are effectively burning rainforests in our gas tanks,'' she said.

However, there could be benefits from planting crops for biofuels on degraded land, such as fields that are not offering low productivity due to salinity, soil erosion or nutrient leaching.

''In a sense that would be restoring land to a higher potential,'' she said. But there would be costs in fertilizer and improved farming practices.

In some cases simply allowing the degraded land to return to forest might be the best answer, she said.

BAC Results Retest

2009-02-13T05:52:00.000-08:00

The answer key for the retest has been corrected.

Here are the results of the meeting with the BAC on Wednesday. The committee brought me four questions to look at.

Question 12.

The correct answer for this question is (b). A mutualism is an interaction between two species in which both species gain a benefit. This is true when there is reciprocal altruism between different species of birds.

Correct answer (b)

Question 27.

The correct answer is (c). Some peopole argued that a similar question was on a past test that showed answer (a) as correct. The purpose of showing you old exams is to give you some idea of the form that the questions will take. This question was not on any information that I supplied you this year.

Correct answer (c)

Question 29.

The correct answer is (b). Some people tried to argue that (a) is also correct so ansswer (d) should be a suitable answer. However, by definition dN/dt = rN any time that r is not equal to zero, dN/dt must depend on population size.

Correct answer (b)

Question 30.

I wrote this question thinking that males fertilizing a female in pines was an example of exploitative competition (when an egg is fertilized it is effectively "consumed" because so other male can fertilize it). However, the way I wrote the question the same logic could be used to choose (b) as a correct answer. this confusion caused several students to choose answer (e). Thus, there is no best answer. I will throw out this question and everyone will receive credit for it.

Photosynthesis- Summary

2009-02-12T12:48:00.000-08:00

One you understand the light dependent reactions, the light independent reactions, and how these two sets of interactions are linked together then you understand the basics of photosynthesis. The pattern of photosythesis that we have discussed so far is known as "C3 photosynthesis" (it is named this becasue the first stable product of the Calvin Cycle is a molecule that contains three carbon atoms). C3 photosynthesis is considered to be the basic mechanism of photosynthesis.

As I have mentioned in class the best way to assure that you understand what is going on is that you should be able to describe photosynthesis at different levels of detail.

1) the one sentence answer
2) the one paragraph answer
3) the full detail answer

In my experience, students quickly get lost by worrying about the details. Thus, I suggest that you start at the one sentence answer, then move to the one paragraph answer, and finally finish up with the full detail answer. You will find that by thinking about the one sentence and the one paragraph answers you will have already figured out how to organize your full detail answer.

I suggest that you try writing out the answers to these questions at the three levels.

1) What is photosynthesis?
2) What are the light dependent reactions of photosynthesis?
3) What are the light independent reactions of photosynthesis?
4) What is a photosystem?

I encourage you to post your answers here and then to provide critical feedback to your classmates about their answers.

Photosynthesis- Light Independent Reactions- Calvin Cycle

2009-02-12T12:03:00.000-08:00

In the light independent reactions the energy stored in ATP and NADPH is converted to energy stored in glucose. This invovles a chemical cycle known as the Calvin Cycle.

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- discuss what links the light dependent and light independent reactions of photosynthesis
- describe the initial step of the Calvin Cycle
- describe the chemical reaction catalyzed by the enzyme RuBP carboxylase
- discuss some interesting characteristics of RuBP carboxylase
- define "carbon fixation" and identify the carbon fixation step in the different modes of photosynthesis
- diagram the Calvin Cycle (at the level of detail that I talked about in class)
- discuss where and why ATP and NADPH are required in the Calvin Cycle
- disucus where in the cell that the Calvin Cycle takes place

Further Viewing

1) This is an excellent animation (narrated by a man with a perfect "announcer's voice"). This animation goes into the amount of detail you are required to know for this class. It even has its own quiz, so see how you do.

http://highered.mcgraw-hill.com/sites/0070960526/student_view0/chapter5/animation_quiz_1.html

2) I didn't know that photosynthesis was such a popular subject for musicians (I can't belive I gave up what would surely have been a lucrative career as a rock star to become a biologist- who knew I could have combined the two). The guy in the video is kind of a dufus, but the song is pretty cool, and I learned something from watchig it.

http://www.youtube.com/watch?v=OYSD1jOD1dQ

3)This is quite a good video (sorry, no song involved). Note, this video concludes that glyceraldehyde phosphate is the result of the Calvin Cycle. For our purposes in this class we are going to conclude that glucose is the end result of this cycle.

http://www.youtube.com/watch?v=mHU27qYJNU0

4) Maybe you will find this animation to be helpful

http://www.science.smith.edu/departments/Biology/Bio231/calvin.html

Photosynthesis- The Light Dependent Reactions

2009-02-12T09:50:00.000-08:00

Photosythesis takes place in two steps. In the first step, known as the light dependent reactions, light energy is converted into chemical energy held in the bonds of ATP and NADPH.

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- list the parts of a photosystem
- discuss the function of a photosystem
- describe where the light dependent reactions of photosythesis occur and discuss why these reactions occur in this location
- describe cyclc electron flow, be able to explain both the energetic result and what chemcical changes occur
- describe non-cyclic electron flow, be able to explain both the energetic result and what chemical changes occur
- describe the cause and the result of chemiosmosis
- answer the question- "why doesn't photosynthesis stop after the production of ATP and NADPH in the light dependent reactions

Further Reading

Here is a link to some fairly detailed info about photosynthesis (it contains some very good diagrams).

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html

Further Viewing

These videos contain animations that might help you to understand what is happening in the light dependent reactions. I encourage you to watch each of these videos.

1) This video has some great animations of what is going on in the light dependent reactions.

http://www.youtube.com/watch?v=hj_WKgnL6MI

2) This short video is a good review of the light dependent reactions.

http://www.youtube.com/watch?v=eY1ReqiYwYs&feature=related

3) This is a video of a woman with a very southern accent talking about photosyntheis with some decent animations.

http://www.youtube.com/watch?v=RFl25vSElaE&feature=related

4) This one comes complete with a "Photosyntheis Song." I guarantee that you will be humming this as you walk around campus!

http://www.teachertube.com/view_video.php?viewkey=dc9810ac32b3c413fb29

Intro to Energetics

2009-02-12T06:42:00.000-08:00

Energy is required to do work. In order to understand the two important energetic processes taking place in living organims (photosynthesis and cellular respiration) it is useful to understand some basics of energetics.

Expected Learning Outcomes

By the end of the course a fully engaged student should be able to

- give examples of biological work
- list different forms of energy, give examples of the different forms, and give examples of energy conversions
- define the First and Second Laws of Thermodynamics and discuss why these laws are important for biologists
- discuss electromagnetic energy, including the wavelengths associated with different forms of electromagnetic energy and the relationship between wavelength and energy
- define a photon
- discuss the three things that can happen when a photon of light hits a molecule
- define a pigment
- draw and interpret an absorption spectrum

Further Reading

Electromagnetic radiation- http://www.eoearth.org/article/Electromagnetic_radiation

Retest BAC and 1st Midterm Essay Regrades

2009-02-11T06:32:00.000-08:00

Retest BAC

If you have comments to submit to the BAC you may either put them in the box on the ledge outside of Dr. Dini's office (there must be received by 3:30) or email them to me (these must be received by 1:45)

Essay Regrades

If you feel that there has been a significant mistake in how your essays fromthe first midterm were graded then you need to type out a description of why you feel that your answer was not fairly graded. Please make sure that you have read the answer key that I posted on the web! There is nothing more frustrating to me than reading a comment from a student that says "I put down everything in the answer key!". The order of words does matter!!!

Please turn these in the box outside my office (r00m 215) in McClellan Hall by 12:00 (noon) on Friday Feb 14th.

MC answers for Retest

2009-02-11T06:26:00.000-08:00

1. d
2. b
3. b
4. c
5. a
6. a
7. c
8. d
9. a
10. d
11. c
12. b
13. c
14. e
15. a
16. b
17. e
18. b
19. e
20. a
21. e
22. d
23. c
24. a
25. c
26. a
27. c
28. e
29. b
30. omitted from exam

Essay Questions Answer Key

2009-02-09T04:56:00.000-08:00

Graph Question

the graphs have been a pain to post so I will show them in class.

b) Over time, the population size increases until the population size reaches the carrying capacity (100 ind) where it remains.

Initially the population growth rate is at its maximum. Over the time the population growth rate decreases until the population growth rate equals zero where it remains.

c)

d) Over time the population size decreases until the population size reaches its carrying capacity where it remains.

Initially, the population growth rate is very negative. Over time the growth rate becomes less negative until the population growth rate reaches zero where it remains.

If you answered the questions about lyrebirds

Male lyrebirds have two distinctive characteristics. First, they produce an elaborate lyre-shaped tailed that they use in mating displays. Second, male lyrebirds are uncanny mimics. In addition, to being able to mimic the sounds of other birds living in the forest, they are also able to mimic human-produced sounds that they hear. It is possible that female lyrebirds examine both the tail and mimicking ability when choosing the mate.

Many females choose to mate with males with extreme traits. Thus, female lyrebirds might be selected to mate with the male with the longest tail. There are two hypotheses that explain why females should choose to mate with males with extreme traits- (1) the handicap principle and (2) the sexy sons hypothesis.

According to the handicap principle, the long tail of the lyrebird makes it more difficult for the males to move about the forest and increases their likelihood of dieing. Thus, a male with an extremely long tail is carrying a large handicap. A male with a long tail who has been able to survive in spite of that handicap must have genes that code for particularly vigorous survival skills. Thus, by choosing to mate with a male with the longest tail the female ensures that she is mating with a male with good survival skills and hopefully those survival skills get passed on to both her sons and her daughters who in turn should have higher survival.

According to the sexy sons hypothesis, if females prefer to mate with males with extreme traits, then any female who mates with a male with less extreme traits will produce sons with less extreme traits so her son will not be attractive to other females. Thus, female lyrebirds may choose to mate with males with the longest tails because in doing so they will produce sons with long tails who will thus be more effective at mating with females.

Females often prefer to mate with older males because older males have proven that they are good at surviving. If male lyrebirds learn to copy sounds over time, then it is possible that older birds are able to mimic more sounds than younger birds. Thus, females who chose to mate with males who mimicked more sounds might benefit because they pass on good genes for survival to both their sons and their daughters who should therefore have higher survival ability.

It is likely that female lyrebirds would use both tail length and number of songs sung as a way of choosing mates. Two signals of males genetic quality would allow females to make more effective choices than if they relied on only one trait.

If you answered the question in general

Females use a variety of means to determine who is the “best male”. What it means for a male to be “best” depends upon whether or not males provide resources to the female before mating or help the female to care for the baby after it is born. In these cases, the best male is the male that provides the most resources because the female can use these resources to make more or stronger babies. For example, in scorpionflies females prefer to mate with the male who provides them the largest food gift at the time of mating. Studies have shown that females that eat a larger food gift are able to produce more eggs. Similarly, this might explain why human females are attracted to wealthier men (e.g., Anna Nicole and the billionaire).

In most cases, the only thing that a male provides to the female is DNA, so the best male is the male that has the “best genes”. Good genes are those that code for traits that make males good at surviving or reproducing. Thus, if a female mates with males with good genes, the desireable traits should end up in her offspring. Experiments, for example in mice, have shown that females are able to choose to mate with the male with the best genes.

The cues that females use to identify the male with the best genes vary across species. Females would like to mate with a male that is good at survival (the result of finding food, resisting predators and disease). The best way for a male to show he is good at survival is for them to have lived for a long time so females of different species use a variety of cues to determine which males is oldest (e.g., deep croak in frogs, song repertoire in mockingbirds). Females would also like to be able to determine if males are generally good at foraging (e.g., female guppies choosing males with more red spots). Females would like to be able to choose males that are healthy. One indication of general health is symmetry so females prefer to mate with symmetric males. Another indication of health is skin coloration in some species of birds and mammals that use patches of skin in mating displays. Skin coloration is influenced by the health of the male; diseased males have duller skin than healthy males so females should choose to mate with males with brighter skin. A male might also show that he is healthy by carrying around some sort of an extreme trait that acts as a handicap to his survival. Thus, by choosing to mate with this male the female is passing on good survival genes to her sons and daughters (handicap principle).

Global Carbon Cycle and Global Warming

2009-02-05T11:41:00.000-08:00

Human activity, including burning fossil fuels, deforestation, and buring trees, has altered the global carbon cycle. This alternation of the global carbon cycle is the proposed cause of global climate change (global warming).

Obviously, global climate change is a very imporant issue facing us today. If you are alive and paying any attention, then you probably know that there is some disgreement out there about (1) whether global warming is occuring, (2) if it is occuring is it a natural occurence or is it caused by humans, and (3)what should we as individuals and a society do about these issues. As I mentioned in class, it is very important that you understand what components of the debate are facts and what components of the debate are based on mathematical models or other forms of argument. I think that it is important that you should be able to explain to other people why scientists will never be able to conduct the experiment that will nail down whether or not humans are causing global warming (we have only one earth).

Unfortunately, there is a lot of misinformation about this topic. For example, on Thursday February 5th there was a letter to the Lubbock Avalanche Journal about global warming that clearyly contained some misstatements of fact. I think that it is important for you to have access to good information. Here are some links to what I consider to be some of the best and most reliable sources of information about this topic. Although some of these articles go into much more detail than are required for this class you should know where to find reliable information about this topic.

Further Reading

Carbon cycle- http://www.eoearth.org/article/Carbon_cycle

Global warming- http://www.eoearth.org/article/Global_warming

Global warming Frequenty Asked Questions- http://www.eoearth.org/article/Global_warming_frequently_asked_questions

Climate change FAQ- http://www.eoearth.org/article/Climate_change_FAQs

Intergovenmental Panel on Climate Change- http://www.eoearth.org/article/Intergovernmental_Panel_on_Climate_Change_%28IPCC%29

IPCC Assessment for Policymakers- http://www.eoearth.org/article/IPCC_Fourth_Assessment_Report%2C_Working_Group_I%3A_Summary_for_Policymakers

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- diagram the global carbon cycle
- discuss how humans have altered the global carbon cycle
- discuss how the atmospheric concentration of carbon dioxide varies annually
- discuss the proposed relationship between human caused changes in the global carbon cycle and global warming
- discuss alternative causes of global warming
- discuss the experiment that would be required to determine whether or not human activity is the cause of global warming
- articulate and defend their own personal view of how they intend to deal with the global warming issue

Saturday Update

The Saturday(February 7, 2009) issue of the Lubbock Avalance Journal contains another letter to the editor talking about global warming. The letter right refers reader to a site, www.petitionproject.org, where they claim that over 30,000 scientists (9000 of them have Ph. D.s) have signed a petition "firmly disagreeing with global warming theory". I would be interested in what you guys thought about the information available on this site relative to the info on the posts I have listed above.

Ecosystem Ecology

2009-02-05T10:59:00.000-08:00

Ecosystem ecologists focus on the flow of enery and the cycling of nutrients through the ecosystem.

Further Readings

Ecosystems- http://www.eoearth.org/article/Ecosystem

Ecological energetics- http://www.eoearth.org/article/Ecological_energetics

Nitrogen cycle- http://www.eoearth.org/article/Nitrogen_cycle

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- diagram and discuss the flow of energy through an ecosystem
- diagram, discuss the causes of, and discuss some of the implications of the enegy pyramid
- diagram nitrogen cycle within an ecosystem
- discuss the factors that influence the rate of flow from dead bodies to the soil and discuss the implications of differences in this rate

Community Ecology- The Portal Experiment

2009-02-05T10:49:00.001-08:00

Here are some photos from the research site in Portal, Arizona. For more information about the research project at Portal you can look at their website at
http://www.biology.usu.edu/labsites/ernestlab/portal/index.html

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- distinguish between direct and indirect, positive and negative effects
- describe the experiemental design that Dr. Brown and his colleagues used to study exploitative competition between desert rats and rodents
- discuss the "search the the missing indirect positive effect of rodents on ants" and how that dilema was solved
-discuss why and how the outcome of studies of interactions betwen organisms can vary over time
- discuss the way that the ecological community responded when they learned the importance of long term studies
- discuss how indirect interactions influence my facvorite phrase "the world is complicated"

BAC Results

2009-02-04T17:22:00.000-08:00

The BAC met at 4:00 PM on Wednesday afternoon to review concerns that people had about the test.

The committee reviewed all of the comments that people turned into me on paper and via email. After meeting the committee brought three questions to me for consideration.

Question #8 (green test-2) #12 (blue test-1)

This question is not clearly worded. Several people asked me questions about this question during the exam and I told them to answer the question one way. When I rereade the question after the exam I saw that there was a justifiable different way to interpret the question.

Thus, for this question both answers a and d will receive credit

Question # 23 (green test-2) #26 (blue test-1)

Cryptic coloration is an adaptation to either capturing prey, catching prey or both. I don't think that cryptic coloration has anything to do with attracting mates (how could being hard to see be a good tactic for attracting a mate?). Thus, I clearly think that answer d is the best answer. However, when I cut and pasted the question from form 1 to form 2 answer e was deleted from form 2. Thus, students taking the blue test had the option to pick a wrong answer that was not available to the students who took the blue test which is unfair.

Thus, for this question I will award credit for both answers d and e

Question #12 (green tetst-2) #8 (blue test-1)
The key phrase in the paragraph associated with this question is " scientists have documented that healthier males are able to produce longer eyestalks than those produced by less healthy males". This sentence tells me that large eyestalks are a signal of health. Thus, females who choose to mate with males with large eyestalks should pass on those genes for "good health" to their offspring (both sons and daughters). Thus, I consider answer d to be the best answer.

Many students thought that females should benefit from producing sons that were better at mating. It is possible that if her sons remained healthy for their whole life that they would produce traits that would make them popular with females. However, this is not as likely as producing healthy sons and daughters.

The key in answering this question is to choose the best answer. If the female is mating with a male with "healthy" genes then these genes should be expressed in both sons and daughters. Thus, I might have awarded credit for an answer that said a, b, and c were true, but because that was not an option.

Thus, only answer d will receive credit.

I would like to thank all members of the BAC for taking an hour out of their day to try to make sure that the testing process is as fair as possible.

Interesting Video from Kruger Park in South Africa

2009-02-04T06:25:00.001-08:00

One of your fellow students just sent me a link to this video. It seems like almost everything that we have talked about so far in BIOL 1404 is going on in this video. The highlight of my biology life was visiting Kruger Park when I was about 13 (how sad to peak so young). I saw lots of amazing animals, but I didn't see anything like this. Enjoy!

http://www.youtube.com/watch?v=LU8DDYz68kM

First Midterm - Answer Key and BAC Info

2009-02-04T06:03:00.001-08:00

Here are the answers for both forms of the multiple choice portion of the test.

BAC

The Biology Advisory Committee will meet with me this afternoon at 4:00 to discuss test questions. If you thought that there was a problem with one of the test questions here is what you need to do.

1. Write a thoughtful statement explaining to me how a student with a strong understanding of biology could have chosen a different answer.

2. You may turn these into me either on paper or via email.

Paper- I will place a box on the ledge outside of Dr. Dini's office. Comments submitted via paper must be in that box by 3:30 on Wednesday

Email- you may send me your comments via email. These comments must be received before 1:45 PM on Wednesday.

Answers Midterm #1

Form 1

1. b
2. a
3. c
4. b
5. c
6. c
7. c
8. d
9. b
10. d
11. c
12. d or a
13. a
14. d
15. b
16. c
17. d
18. b
19. a
20. b
21.c
22. c
23. d
24. b
25. e
26. d or e
27. e
28. c
29. b
30. a

Form 2

1. b
2. a
3. c
4. b
5. c
6. d
7. c
8. a or d
9. a
10. c
11. c
12. d
13. b
14. c
15. d
16. b
17. d
18. b
19. c
20. d
21. b
22. e
23. d or e
24. e
25. c
26. b
27. a
28. a
29. b
30. c

HHMI Undergraduate Research Fellowships

2009-02-03T13:40:00.001-08:00

As I mentioned in class, the HHMI Undergraduate Research Fellowships are one of the great opportunities that we are able to offer students at Tech. If you are interested in gaining some research experience I urge you to check this program out.

The application deadline is February 25th, so it is time to get started!!!

For more info check out the website-

http://www.ciser.ttu.edu/hhmi/default.aspx

The people working with HHMI are all very nice and will help you with any questions or problems that you have. Tell them that I sent you and they will treat you especially well!

Reviews for First Midterm Exam

2009-01-31T10:53:00.001-08:00

Group Office Hours

I will hold group office hours on Monday evening, February 2nd starting at 5:30 in room 23 in the basement of the Biology Building. I will hang around as long as anyone has any questions.

SI Marathon Review Session

Jimmy will hold his SI Marathon Review session-

Monday, February 2, 2009
7:30pm-10:30pm
Holden Hall 104

This is Cool!

2009-01-28T11:39:00.000-08:00

Here are some photos that someone forwarded to me. This has nothing to do with the class other than to show how fantasitcally cool biology can be. Enjoy

Mass Migration of Rays

Looking like giant leaves floating in the sea, thousands of Golden Rays are seen here gathering off the coast of Mexico . The spectacular scene was captured as the magnificent creatures made one of their biannual mass migrations to more agreeable waters.

Gliding silently beneath the waves, they turned vast areas of blue water to gold off the northern tip of the Yucatan Peninsula . Sandra Critelli, an amateur photographer, stumbled across the phenomenon while looking for whale sharks.

She said: 'It was an unreal image, very difficult to describe. The surface of the water was covered by warm and different shades of gold and looked like a bed of autumn leaves gently moved by the wind.

'It's hard to say exactly how many there were, but in the range of a few thousand'

'We were surrounded by them without seeing the edge of the school and we could see many under the water surface too. I feel very fortunate I was there in the right place at the right time to experience nature at its best'

Measuring up to 7ft (2.1 meters) from wing-tip to wing-tip, Golden rays are also more prosaically known as cow nose rays.

They have long, pointed pectoral fins that separate into two lobes in front of their high-domed heads and give them a cow-like appearance. Despite having poisonous stingers, they are known to be shy and non-threatening when in large schools.

The population in the Gulf of Mexico migrates, in schools of as many as 10,000, clockwise from western Florida to the Yucatan .

Community Ecology I

2009-01-27T15:03:00.000-08:00

Community Ecology will be the final topic covered on the First Midterm (Monday's lecture will be included on the exam). You are responsible for the material on pages 1198 - 1210 on this exam. You are NOT responsible for any material on Ecosystems on this exam.

Suggested Readings

Community Ecology- http://www.eoearth.org/article/Community_ecology

Competition- http://www.eoearth.org/article/Competition

Interspecific Competition- http://www.eoearth.org/article/Interspecific_competition

Exploitative Competition- http://www.eoearth.org/article/Exploitative_competition

Predation- http://www.eoearth.org/article/Predation

Mutualism- http://www.eoearth.org/article/Mutualism

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- define competition, exploitative competition and interference competition

- identify and explain examples of exploitative and interference competition from a variety of environments

- define predation (narrow and broad sense), herbivory, and parasitms

- identify and explain examples of predation, herbivory, and parasitism from a variety of environments

- identify examples of morphological and behavioral adaptations that animals have to help capture their food

- identify examples of morphological, biochemical, or behavioral adaptations that animals have to protect them from predators

- identify and explain examples of mutualisms from a variety of habitats

- explain the results of Connell's experiment examining competition between two species of barnacles (Fig. 54.3) and Paine's experiment examining predation by the starfish Pisaster (Fig. 54.15)

- define a keystone species and an ecosystem engineer and provide examples of each.

Past Test Questions (answers at bottom of post)

In the southeastern United States, a weedy plant called Kudzu has caused a great deal of problems. Because Kudzu has such high growth rates it is able to rapidly overgrow buildings and other plants.

1. Which of the following would best describe the ecological relationship between Kudzu and a species of pine tree that is commonly overgrown by Kudzu?
(a) mutualism
(b) parasitism
(c) exploitative competition
(d) herbivory
(e) none of the above

Answer- 1. c

Classes for Wednesday January 28th, 2009

2009-01-27T14:40:00.000-08:00

They just announced that classes will be delayed until 10:00 AM on Wednesday January 28th because of bad weather. This means that the 9:00 AM lecture (BIOL 1404 section 001) is cancelled while the 10:00 AM lecture will take place.

This causes a few problems because we have a test scheduled for Tuesday night and I want both of the sections to have covered the same material. Here is what I propose to do.

1) I will delay finishing the discussion about logistic growth until Friday in both sections. I have already posted a couple of lessons about logistic growth and it probably would not be a bad idea for you to examine those before Friday.

2) If there is time on Friday I will begin the next topic- Community Ecology (if there is not time we will start this topic on Monday). I will soon make a post about what information about Community Ecology you are responsible for on the first midterm.

3) During the 10:00 AM lecture on Wednesday I will talk about human population growth. Students in both sections will be responsible for the information covered in the readings and in the web post on Human Population Growth. I think that this is a very interesting and important topic and I will go into more detail in Wednesday's 10:00 lecture than you will be responsible for on the test. Any students who are enrolled in the 9:00 section that are able to attend the 10:00 section are encouraged to attend. I think that human population growth is one of the most interesting and important issues facing us today, so I look forward to discussing it with you.

Human Population Growth

2009-01-27T14:06:00.000-08:00

I have spent a lot of time telling you that exponential growth is an unrealistic model of population growth. Interestingly, human populations have experienced exponential-like growth. How can this be?

What makes humans different from other species?

In other species per capita birth rates and per capita deaths rates are density dependent. However, as human populations have increased there has been no corresponding decline in per rates or increase in death rates. What makes humans different from other species?

Humans have the ability to alter their environment so that they can avoid the density dependent effects on birth and death rates. 1) Humans have increased food production by improvements in agriculture (e.g., irrigation, fertilization, mechanized farming, genetically improved crops). 2) Humans have been able to decrease death rates by improvements in medicine and public health (things as simple as not pooping in the water you drink helps a lot!). 3) Humans have elimnated most human predators (ocassionally, someone gets killed by a shark or a mountain lion).

Where is human population growth occuring?

The rates of human population growth are not the same in all regions. Today, human populations are increasing in size much faster in developing countries (e.g., Mexico, other countries in Central America, Africa, and Southeast Asia) than they are in developed countries (e.g, USA, Canda, Western Europe). The figure at the top of this post shows the patterns of population growth in developed and developing nations.

Thus we see that populations are increasing most rapidly in the countries that are least able to deal with a rapidly increasing population. See "Population Challenges-The Basics" that can be downloaded from the Population Institute's website.
http://www.populationinstitute.org/population-issues/index.php

Human Population Growth Proble?

There is a great deal of debate about whether increasing human populations are a problem or not, and if they are what should be done about it. Unfortunately, we don't have time to discuss this issue in very much detail in class. My personal opinion is that we have too many people consuming too many resources and the last thing that we need are billions more people living on the planet. This is an issue that I am always intersted in talking more about if you would like to chat.

Further Reading

The section on Human Population Growth in your textbook is quite good.

Also see the article "Human Population Explostion" from the EoE.
http://www.eoearth.org/article/Human_population_explosion

Both of these contain a good discussion of the "demographic transition".

Really Cool Video

Here is a link to a YouTube video on "World Population" The first minute and a half or so is a little boring, so you can skip over it if you wish. However, I think the animation showing when and where human population growth has been occuring is really cool.

http://www.youtube.com/watch?v=4BbkQiQyaYc

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- describe patterns of human population growth in developed and developing nations
- discuss some reasons why the pattern of population growth in humans is so different from that in other species
- describe the demographic transition
- discuss their own personal view of human population growth.

Past Test Questions (answers at bottom of post)

1. In developing countries, why have per capita birth rates not decreased as human populations have increased in size?
(a) because we have increased rates of food production
(b) because of the improvements in education of women
(c) because of improvements in medical care
(d) a and c
(e) a, b, and c

2. Why do some people consider the high growth rates of human populations in developing countries to be of concern?
(a) because many people are born into conditions that do not provide them enough food
(b) because many people are born into conditions without clean water and adequate sanitation
(c) because increasing population sizes have led to increasing habitat destruction
(d) a, b, and c
(e) none of the above

answers- 1.d, 2.d

Population Growth IV- Final Thoughts

2009-01-27T10:44:00.000-08:00

We have discussed how population ecologists have tried to develop a model (the logistic growth model) that helps them to understand the factors that affect population growth.

We talked a lot about the graph plotting how the populaiton size would vary over time in a population that started much smaller than the carrying capacity (the s-curve). Why does logistic growth show this pattern.

Initially, the population is growing slowly. When populations are small the per capita growth rate is large but because there are only a few individuals in the population rN is small. Over time, the population growth rate increases becasue populations are still small enough that r is still relatively large and now a larger N allows rN to be a bigger number. Population growth rate starts to slow as populations reach their carrying capacity because in large populations the per capitat growth rate is small and even though N is large rN is small. When the population reaches its carrying capacity b = d, so population growth stops.

Density Dependent Population Regulation

We notice that populations don't keep increasing in size forever. That is because populations are naturally self regulating. As population size increases the per capita birth rate declines for the biological reasons that we discused earlier. (When a parameter decreases as population size increases that parameter is said to be negatively density dependent. As population size increases the per capitat death rates increase for the biological reasons that we discussed earlier. (when a parameter increases as the population size increases that parameter is said to be positively density dependent). Thus, the per capita birth and death rates are naturally density dependent in such a way that eventually causes the population size of species to stop growing.

Past Test Questions (answers at bottom of post)

1. In logistic growth, what is the per capita growth rate when N = 1/2K?
(a) rmax
(b) 2(rmax)
(c) ½ (rmax)
(d) it is a maximum
(e) you can not answer this questions with the information provided.

2. How can you calculate the population growth rate?
(a) subtract B from D
(b) add the per capita death rate to the per capita birth rate
(c) multiply r by N
(d) divide dN/dt by N
(e) a and c

3. Why don’t we expect raccoons to show exponential growth?
(a) per capita birth rates increase as population sizes increase
(b) per capita death rates increase as population sizes increase
(c) per capita birth rates decrease as population sizes increase
(d) b and c
(e) none of the above

4. Which of the following are true when populations are at their carrying capacity?
(a) dN/dt > 0
(b) r < 0
(c) b = d
(d) B > D
(e) a and d

answers- 1.e, 2.c, 3.d, 4.c

Final Thought About Sexual Selection- The Exception that Proves the Rule

2009-01-27T10:29:00.000-08:00

When I introduced the topic of sexual selection I mentioned that the critical difference between males and females was the size and function of their gametes and that that difference was the cause for many of the differences between males and females we are familiar with. Because they typically invest more resources in each offspring we expect that females should be choosy about who the mate with and that males should compete for the opportunity to mate with females. Sexual selection has resulted in the production of brightly colored and ornamented males who use coloration and ornamentation to attract females.

Thus, when we see sexual dimorphism in birds we generally conclude that the brightly colored individual is the male while the dull colored individual is the female. At the top of the page is a picture of a male and female Red Phalarope. Based on what we have learned so far it would be easy to conclude that the brightly colored bird was a male. However, if you did so, you would be wrong! How can this be?

It turns out that phalaropes, and othe birds like them, are the exception that proves the rule. Phalaropes have a polyandrous mating system (one female mates with many males). After a female phalarope mates with a male she lays the eggs which are taken care of by the male. While the male is looking after the eggs, the female heads off in search of another male to mate with. Thus, in polyandrous birds, the investment of time by the male actually means that the male invests more in each offspring. Thus, in polyandrous species males are more choosy about who they should mate with than are females and females are brightly colored in an attempt to attract males. Pretty cool!!!!

Schedule for First Midterm

2009-01-26T06:37:00.000-08:00

The 1st midterm is exam is scheduled from 6:00 to 7:30 PM on February 3rd, 2009. I believe that you will take the exam in your normal classroom (if this is not the case then I will make announcements in class and post on the blog).

The retest for the 1st midterm is scheduled from 6:00 to 7:30 PM on February 19,2009.

Group Selection

2009-01-26T06:10:00.000-08:00

In class on Friday morning someone asked the question "Why doesn't group selection work?". This is a good and important questions. Unfortunately, we are just a little bit behind schedule so I am sorry that I wasn't able to spend the time in class to answer this question. Let me try to answer the question here.

Group selection is the hypothesis that organisms have the traits they do (including altruistic traits) because selection has produced traits that assure that species survive. Although this is intuitively an OK idea, it turns out that it doesn't work.

Have you ever noticed large "roosts" of birds in trees around town. Roosting birds gather by the hundreds or thousands in one, or a few, trees (maybe you have mistakenly parked you car underneath a roost and suffered the consequences). Biologists are interested in understanding the causes of roosting behavior. People who support the group selection hypothesis have proposed that the reason that these birds are roosting is that it gives them an opportunity to examine how large their population is. Becasue the birds do not want to overpopulate their environment, because overpopulation could lead to a loss of all of the food so that the entire species dies, birds want to know how many other birds are there so they know how much to reproduce. If birds see that the roosts are large then they know that the population is large so they decide to produce only a few babies. However, if the birds see that the roost is small then they are decide to produce many babies. Thus, the population never gets so large that they eat up all of the food.

Unfortunately, the math required for group selection just doesn't work out. Imagine a species of birds that mated monogamously for life. If the parents wanted to keep population sizes constant than their best strategy would be to produce two offspring during their life so that they make just enough kids to replace themselves. For this to happen all females would have a gene that said "make two babies". Imagine that a mutation occurs that says "make three babies". This mutation would quickly spread througout the population so that eventually all females would produce babies. If mutations that said produce 4 or more babies occurred then these mutations would also spread. It is thus possible to imagine that each female would make so many babies that the population would indeed get large enough to consume all of the food which would cause the population to go extinct. Thus, the math of natural selection does not allow organisms to artificially reduce their fitness for the "good of the species".

The observation that led group selectionist to thinking that roosting and reproduction could be explained by group selection was that females produced fewer eggs when more individuals were at the roost than when fewer individuals were at the roost. Can you think of another hypothesis to explain this observation?

So why do birds form roosts? There are at least two hypotheses. First, some scientists propose that organisms roost because they are safer from predators when living in large groups. Others think that organisms form roosts because they can benefit from information gained by living with lots of other individuals. For example, if you flew to the south to look for food and didn't find much and you noticed that those birds returning to the roost from the north looked well fed, then you might head out to the north the next day.

Fun With Graphs- Quiz Yourself

2009-01-25T16:24:00.001-08:00

Here are some questions that I have designed to let you know if you are understanding the graphs well enough to meet the course expected learning outcomes. I suggest that you do not try to answer these questions until you have thoroughly reviewed all of the information about the population ecology graphs. (I will put the answers for the multiple choice questions at the bottom of this post, for the others you need to find out whether your answers are correct or not).

1. What are the correct axes for a graph showing how population growth rate depends on population size in logistic growth?

a) x- N y- t
b) x- N y- dN/dt
c) x- dN/dt y- N
d) x- dN/dt y- t
e) x- N y- r

2. Which of the following best describes the graph that shows how the per capita growth rate varies over time in exponential growth?

a) the per capita growth rate decreases over time
b) the per capita growth rate increases over time
c) the per capita growth rate does not change over time
d) the per capita growth rate increases until it reaches a maximum and then decreases to zero when the population reaches the carrying capacity
e) the per capita death rate is initially very negative and gets less negative over time.

3. What would I ask to make you draw this graph?
a) show how the population size varies over time in logistic growth when the initial population size is much smaller than the carrying capacity
b) show how the population growth rate depends on the population size in logistic growth when the intitial population is much smaller than the carrying capacity
c) show how the population size depends on population size in logistic growth when the initial population size is much smaller than the carryuing capacity
d) show how the population size varies over time in logistic growth when the intitial population is much larger than the carrying capacity

4. What are the axes of a graph showing how the per capita growth rate depends on the population size in logistic growth?

a) x- logistic y- exponential
b) x- logistic y- r
c) x-N y-r
d) x-r y-N
e) x-N y-dN/dt

5. Which of the following is true when populations are at their carrying capacity?

a) N = 100 individuals
b) dN/dt = 0
c) b > d
d) b = d
e) b and d

6. Describe how the population growth rate varies over time in logistic growth when the intial population size is much larger than the carrying capacity.

7. Draw the graph that shows how the population size varies over time in logistic growth when the initial population size is much smaller than the carrying capacity.

Answers. 1.c, 2.c, 3.b, 4.c, 5.e

Population Ecology III- Logistic Growth

2009-01-25T15:57:00.000-08:00

We are trying to develop a mathematical model that helps us to understand patterns of population growth. So far our first attempt, the exponential growth model, did not help us to understand population growth (for reasons that I hope that you understand by now).

The "Real" world

In our attemtp to think about population growth in the real world, we attempted to examine how per capitat birth rates and per capitat death rates should vary as population size varies. The model that describes this pattern of growth is known as the logistic growth model. It is important to realize that although this model is much more realistic, and therefore useful to us, than the exponential growth model, the logistic growth model still only exmaines what I call "the theoretical real world". That is, this model applies to our ideas about how populations should generally behave and do not thus relate directly to studying the population sizes of white tailed deer in central Texas or parrot fish on a coral reef in Fiji. These real world situations are much harder to understand than the simple "idealized" populations that I am talking about in BIOL 1404. You can take an Advanced Population Biology course if you want to learn more about how to apply these models to the "real real world".

Logistic Growth

We have discussed why, in the real world, r should decrease as population sizes increase. If this is the case then there is a population size at which the per capita birth rate equals the per capita death rate. We call this population size the carrying capacity.

1) When populations are smaller than the carrying capacity we expect them to increase in size until they reach the carrying capacity.

2) When populations are larger than carrying capacity we espect them to decrease in size untile they reach the carrying capacity.

3) When the population size equals the carrying capacity we expect no change in the size of the population.

The logistic growth equation is a mathematical equation developed by biologists to describe patterns of population growth consistent with the ideas above. Before focusing on the biological isights that we can gain from the logistic growth model (the real purpose of everything we have been doing) it is important to really understand patterns of logistic growth. Hopefully, this powerpoint presentation will help you understand these patterns better.

Powerpoint Presentation

Click here for a powerpoint presentation entitled "Fun With Graphs- Logistic Growth"

http://www.slideshare.net/secret/gyB3cjnSplLw41

Expected Learning Outcomes

By the end of this course a fully engaged students should be able to

- define the carrying capacity
- draw, and interpret the following graphs associated with logistic growth
-how population size changes over time in logistic growth when the initial population size is much smaller than the carrying capacity
-how the population size changes over time in logistic growth when the initial population size is much larger than the carrying capacity
-how population growth rate changes over time in logistic growth when the initial population size is much smaller than the carrying capacity
-how the population growth rate changes over time in logistic growth when the initial population size is much larger than the carrying capacity
-how the per capita growth rate varies over time in logistic growth
-how the population growth rate varies over time in logistic growth

- discuss the causes for the shape of the s-curve (this answer will need to include a discussion of both math and biology)

- discuss the factors that regulate population size, be able to distinguish between density dependent and density independent factors that regulate population growth and give examples

Fun Wth Graphs- Exponential Growth

2009-01-23T12:08:00.000-08:00

How do I know which graph to draw?

1) In the population ecology portion of this course we will be discussing two models of population growth- exponential growth and logistic growth. Thus, you need to know which growth model you are describing before you know which graph to draw.

2) You can't draw a graph until you know what the axes are.

Hopefully, this is a review, but it is probably worth talking about. The x-axis (the horizontal axis) is known as the independent variable. The y-axis (the vertical axis) is the dependent variable. Changing the value of the independent variable results in a change in the dependent variable. Id DOES matter which variable goes on which axis so try to get it right.

In population ecology there will be two main independent variables that we are interested in studying. Because we are interested in patterns of population growth, we will often want to observe how variables change over time. Time is always the independent variable, so it always goes on the x-axis. Sometimes we are interested in how parameters depend on population size. In this case, population size is always the independent variable.

Powerpoint Presentation

This powerpoint presentation "Fun With Graphs: Exponential Growth) reviews the graphs you are expected to be able to draw, understand, and interpret.

http://www.slideshare.net/secret/mavlOD8flFs67G

Population Ecology II. Exponential Growth

2009-01-23T06:13:00.000-08:00

From the first lesson on Population Ecology we learned that the population growth rate (dN/dt) can be calculated as the product of the per capita growth rate (r) and the population size (N).

dN/dt = rN

This is the fundamental equation describing population growth and this equation is always true.

If we want to use this equation to analyze how population sizes change over time, then it makes sense to start by examining the simplest formulation of this equation which occurs when the per capita growth rate is constant. The equation dN/dt = rN when r is constant is known as the exponential growth equation and this equation describes a patter on growth known as exponential growth.

The graph plotting how population size changes over time is shown in the Exponential Growth article. This graph shows an exponential growth curve (sometimes known as the "j-curve"). If you have questions about why the graph has this shape let me know and I will try to explain it more thoroughly.

It is important that you are able to look at this graph and determine all of the information held in the graph. The exponential growth curve allows us to discuss how two parameters change over time- 1) the population size (shown by the x-axis) and 2) the population growth rate (shown by the slope of the line). I find that it is easier to discuss only one parameter at a time so let's start with the population size.

1) Over time, the population size increases (we know this because the line has a positive slope).

Now let's think about the population growth rate.

2) Over time, the population growth rate increases (we know this becasue the line gets steeper over time.

3) Over time, the rate at which the population growth rate increases over time, increases over time (we know this because the slope increases faster and faster over time).

Thus, if populations are growing exponentially then they keep increasing in size at an ever faster rate forever and ever.

Now try this-

Can you draw the following graphs?

1) plot how the population growth rate varies over time.
(hint- we have alredy described what this pattern will look like using words- just turn these words into pictures).

2) plot how the population growth rate depends on population size.
(hint- this graph is a little trickier, but we do have an equation that relates the two variables)

3) plot how the per capita growth rate varies over time.
(hint- think about what the basic assumption we made aboiut exponential growth)

4) plot how the per capita growth rate
(see the hint from number 3)

Exponential Growth is Unrealistic
Because population sizes keep increasing at ever faster rates for ever, exponential growth does not seem to be an accurate description of population growth in most animals, plants, and microbes. If this is an unrealistic model then why did I teach it to you? I started with exponential growth becasue it is the simplest model of population growth and scientists always like to describe the world using the simplest models that they can.

Obviously, in this case we have started with a model that is too simple to realistically describe the world. What is wrong with the exponential growth model? The fundamental assumption we made about exponential growth is that the per capita growth rate is constant. This must not be a realistic assumtpion.

It is important that you understand, and are able to explain, both the mathematical reasons and biological reasons that exponential growth is an unreasonable model of population growth. I tried to explain biologically why exponential growth is unrealistic in the "Exponential Growth" article and the attached Powerpoint presentation so take a look at those.

Suggested Readings

Here are some articles you should look at from the Encyclopedia of the Earth. I wrote these so they are brilliant!!!

Population Ecology http://www.eoearth.org/article/Population_ecology

Exponential Growth http://www.eoearth.org/article/Exponential_growth

Logistic Growth http://www.eoearth.org/article/Exponential_growth

Carrying Capacity http://www.eoearth.org/article/Carrying_capacity

Intraspecific Competition http://www.eoearth.org/article/Intraspecific_competition

Powerpoint Presentation

Click here for the Powerpoint presentation "Why is Exponential Growth Unrealistic?"
http://www.slideshare.net/secret/IDPugQtl2wvONv

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- draw and interpret the following graphs associate with exponential growth

a) how population size change over time in exponential growth

b) how population growth rate varies over time in exponential growth

c) how the population growth rate depends on the population size

d) how per capita growth rate changes over time in exponential growth

e) how per capita growth rate depends on population size

- explain why exponential growth is an unrealistic pattern of growth for most species

- define and explain the carrying capacity

Population Ecology I. Basic Parameters

2009-01-23T06:06:00.000-08:00

Here is a brief introduction to some of the important parameters that we will need to understand to be able to study population ecology. For each of the parameters it is important that you know (1) the name of the parameter, (2) the algebraic symbol used to represent the parameter, (3) the units of measurement for the parameter, (4) how to calculate the parameter, and (r) how to describe (in words) what a particular value of that parameter means.

It is probably easiest for me to introduce these concepts using an example.
Imagine that in a population of 100 elephants that in one year 10 elephants are born and 5 elephants die.

1) Population Size (N) units- individuals. Measures the number of individuals in a population.

N = 100 individuals

In this population, there are 100 elephants.

2) Population Birth Rate (B) units- number of births per time. Measures the number of births per time that occur in a population.

B = 10 births/year

In this population, each year there are 10 births.

3) Population Death Rate (D) units- number of deaths per time. Measures the number of deaths per time that occur in a population.

D = 5 deaths/year

In this population, each year there are 5 deaths.

4) Population Growth Rate (dN/dt) units- number of idividuals per time. Measures the rate of change of the population size.

dN/dt = B - D

dN/dt = 10 births/year - 5 deaths/year = 5 individuals/year

In this population, the population size increases by 5 individuals each year.

5) Per Capita Birth Rate (b) units- births per time per individual. Measures the number of births per time averaged across all members of the population.

b = B/N

b = (10 births/year)/100 individuals = 0.10 births/year/individual

In this population, each year 0.10 babies are born for each individual in the population.

6) Per Capita Death Rate (d) units - deaths per time per individual. Measures the number of deaths per time averaged across all members of the population.

d = D/N

d = (5 deaths/year)/100 individuals = 0.05 deaths/year/individual

In this population, each year 0.005 individuals die for each individual in the population.

7) Per Capita Growth Rate (r) units = individuals/time/individual. Measure the rate of change in population size averaged across all individuals. The per capita growth rate can be calcuated two ways.

a) r = b - d

r = 0.10 births/year/individual - 0.05 deaths/year/individual = 0.05 ind/year/ind

b) r = (dN/dt)/N

r = (5 individuals/year)/100 individuals = 0.05 individuals/year/individual

In this population, each year 0.05 individuals are added for each individual in the population.

Practice Problem

In a population of 50 tigers, in one year 10 tigers are born and 20 tigers die. What is B, D, dN/dt, b, d, r?

Sexual Selection- Powerpoint

2009-01-21T13:44:00.001-08:00

Let's see if I am smart enough to put the Powerpoint presentation on the blog. If you click here you should be able to view the Sexual Selection Powerpoint.

http://www.slideshare.net/secret/CG2HHvtrLA1KwL

Genetics of Behavior

2009-01-20T11:51:00.000-08:00

During the first portion of BIOL 1404 I have chosen to examine social behaviors as an example of a genetically controlled trait that can be influence by natural selection. In reality, we don't understand the mechanisms by which genes influence behavior, but we know that it must be quite complicated.

However, we are learning more about this topic all of the time. A recent issue of Science (the most prestigious science publication in the United States) published on November 7, 2008 contained a Special Section entitled "From Genes to Social Behavior". This section reviews some of the recent work on this field and includes articles such as "Parsing the Genetics of Behavior", "Genes and Social Behavior", Oxytocin, Vasopressin, and the Neurogenetics of Sociality, and "Wired for Sex: The Neurobiology of Drosophila Mating Decisions". If you are interested in learning more about this topic, then these articles would be a great place to start.

Sexual Selection

2009-01-19T09:58:00.001-08:00

I think that sexual selection is one of the most interesting topics in all of biology. First, studyign this topic helps to illustrate that natural selection is much more than "survival of the fittest". Second, many of the traits produced by sexual selection are particularly bizzare. Finally, I think that it is fun to use what we have learned about mate choice in animals to helping us to understand human behavior.

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- discuss the critical difference between males and females and discuss how this difference influences differences in behavior and morphology between species.

- discuss why sexual selection is just a subset of natural selection

- discus why females should be choosier about who they mate with than males

- discuss why males often compete with other males to fertilize eggs of females

- compare and contrast male-male competition in species with internal fertilization and species with external fertilization

- describe the studies used by scientists to see if females are capable of choosing the best males

- discuss how females can determine which is the best male

- discuss why the variation in female reproductive success is much less than the variation in male reproductive success

- discuss how you would use sexual selection to help you understand human behavior

Past Exam Questions (answers at the bottom of the post)

1. Why are females choosier than males about who they mate with?
(a) female gametes are much more expensive than male gametes
(b) male gametes are much more expensive than female gametes
(c) in some species, males are larger than females
(d) in some species, males compete to mate with the female
(e) c and d

2. Why should females prefer to mate with the oldest males?
(a) because they can pass on good mating genes to their daughters
(b) because they can pass on good survival genes to their sons
(c) because the can pass on good survival genes to their daughters
(d) a and c
(e) b and c

3. Why might females sometimes cause male-male competition to occur?
(a) to assure that she mates with the oldest male
(b) to assure that she mates with the most symmetric male
(c) the male who wins the fight is likely to have “good genes”
(d) a and c
(e) a, b, and c

Further Reading

Here is a link to a website that a student sent to me last year called "The 30 Strangest Animal Mating Habits" http://www.neatorama.com/2007/04/30/30-strangest-animal-mating-habits/

Take a look at this and see if you can relate what the animals are doing to some of the theories that we have talked about in class.

Here is a link to a youtube video showing the mating display of lyrebirds. I was lucky enough to see a lyrebird doing its mating display when I was a kid living in Australia. There was a professional nature photographer who had been hiking around the bush for a couple of weeks waiting to see the display and he was pissed that my Dad and I were able to see the display after spending only about an hour in the woods. What do you think is going on with the lyrebirds?

http://www.youtube.com/watch?v=VjE0Kdfos4Y

Answers. 1. a, 2. e, 3. c

Antibiotic Resistance

2009-01-18T11:24:00.000-08:00

Expected Learning Outcomes

By the end of this course the fully engaged students should be able to

- discuss the evolution of antiobitic resistant microbes as an example of natural selection
- discuss mistakes by both medical practioners and patients that led to this problem
- discuss how a broad exposure to diverse fields of biology may help future health science professionals.

Further Reading

Here is a link to an in-depth discussion of antibiotic resistance published by the World Health Organization http://www.who.int/infectious-disease-report/2000/other_versions/index-rpt2000_text.html

Past Exam Questions (answers at the bottom of the post)

In the 1950s, Japanese physicians began to notice that some hospital patients suffering from bacterial dysentery, which produces severe diarrhea, did not respond to antibiotics that had generally been effective in the past.

1. In order for the result described above to have occurred, which of the following must have been true in the population of dysentery-causing bacteria?
(a) there was variation in the susceptibility of the bacteria to antibiotics
(b) antibiotic resistance was heritable
(c) bacteria that were more resistant to antibiotics had higher survival rates than less resistant bacteria
(d) a, b, and c
(e) neither a, b, or c was true

2. What can be done in future to limit the problem of antibiotic resistance in disease-causing microorganisms?
(a) Doctors should only describe antibiotics when appropriate
(b) Doctors should prescribe larger doses of antibiotics
(c) patients should make sure to take all of the pills when antibiotics are prescribed
(d) a and c
(d) a, b, and c

Answers 1. d 2. d

The Evolution of Sex

2009-01-15T10:30:00.000-08:00

Based on our understanding of natural selection, at first glance sexual reproduction doesn't appear to be advantageous from the female perspective (due to the two-fold cost of sex). However, the fact that sexual reproduction is so common in all groups of organisms suggests that there must be some major benefits of sex that outweight the costs.

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- explain "the two-fold costs of sex"
- discuss possible benefits of sexual reproduction including adaptation to environmental uncertainty and fighting disease
- be able to discuss the problem of the evolution of antiobiotic resistant microbes
- be able to discuss what the medical field may be able to learn from observing how nature fights disease.

Past Exam Question (answer at the bottom of the post)

1. What is the “two fold cost of sex”?
(a) female gametes are twice as expensive to produce as male gametes
(b) the genetic variation produced by sexually reproducing females provides a benefit if there is environmental uncertainty
(c) individuals reproducing asexually pass on twice as many of their genes
(d) a and b
(e) b and c

2. Which of the following hypotheses can explain a benefit of sex?
(a) males pass on more genes in sexual reproduction than in asexual reproduction
(b) the genetic variation produced by sexual reproductions provides a benefit in uncertain environments
(c) females reproducing asexually pass on twice as many of their genes
(d) a and b
(e) b and c

Further Readings

Although I am usually a little skeptical of articles form Wikipedia, this one is pretty good. It goes into more detail than you need to know, but provides some useful information

Evolution of Sexual Reproduction http://en.wikipedia.org/wiki/Evolution_of_sex

Life in Local Playa Lakes

If you would like to learn a little more about local playa lakes-

Playa Lakes http://www.eoearth.org/article/Playa_lake

Drawings of cladocerans similar to those inhabiting playa lakes.

This is what they don't look like.

answer- 1. c 2. b

Cultural Selection

2009-01-15T10:14:00.000-08:00

In humans there are examples of alturistic behaviors that appear to be difficult to explain by kin selection of reciprocal altruism (e.g. soldiers sacrificing their lives in battle, police or firefighters risking their lives, catholic priests remaining celibate).

Genes are self replicating molecules. Genes produce our bodies which in turn produce more copies of their genes. Richard Dawkins has suggested that we think about genes as being "replicators" and our bodies as being "vehicles" whose job it is to make more copies of the replicators. If we can not explain altruistic behaviors as strategy for increasing the transmission of genes into the next generation them maybe we need to search for another kind of "replicator". Dawkins has suggested that "ideas" (he calls them "memes") are also capable of self replication. Because ideas differ in how long they survive and how well they are passed on it should be possible to have selection for ideas (cultural selection).

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- identify examples of altruistic behavior that might be explained by cultural selection
- be able to compare and contrast "natural selection" with "cultural selection"

Further Readings

Cultural evolution http://plato.stanford.edu/entries/evolution-cultural/

As I mentioned in class, one of my favorite books of all time is "The Selfish Gene" by Richard Dawkings. He discusses some of his ideas about cultural selection in the final chapter of this book. Here is a link to that chapter in case you are interested
http://www.rubinghscience.org/memetics/dawkinsmemes.html

Tropical Marine Biology in Belize!!

2009-01-14T11:19:00.000-08:00

I was pleased when I just learned that the Department of Biological Sciences will be offering Tropical Marine Biology (BIOL 3303) during the first summer session. Although the details are not finalized here is what I know right now. The course will meet in Lubbock for 3 - 4 days prior to leaving for Ambergris Caye in Belize. We will spend two weeks at the Belize Tropical Research and Education Center (TREC). Most days will be spent on TREC's boat, the Goliath, which will take us snorkelling (you need to be able to swim to take this course). In addition, we will make a couple of tours to mainland Belize to visit Mayan ruins, the Belize Zoo, and go cave tubing.

The course will focus on the ecology and organismal diversity of tropical marine ecosystems. You will learn to identify corals, fishes, algae, and other invertebrates (and if we get lucky we will maybe see dolphins, sea turtles and a manatee!) and will study tropical communities including sea grass meadows, the mangroves, and the star attraction- coral reefs. We will have written exams and ID exams in the lab and in the field.

Last year the costs were almost $2900 for travel, room and board, all of the field trips, and a couple of meals out. I have not finalized the costs for this year, but I hope that they are in the same ballpark. In addition, you would need to pay tuition and fees for a 3 hour course.

If you are interested in more information about this cours, then please send me an email at

mark.mcginley@ttu.edu. I will work to finalize the details as soon as possible.

Reciprocal Altruism

2009-01-14T10:54:00.000-08:00

Altruistic acts among non relatives can be understood by reciprocal altruism. As we discussed in class we would expect reciprocal altruism to be limited to species that show long term associations and are "smart" emough to be able to recognize individuals and remember who owes them and who does not.

Examples of Past Test Questions (answers at the bottom of this post)

1. It is not uncommon for college students to share items such as shampoo with their roommates. Which of the following hypothesis best explains this behavior?
(a) group selection
(b) kin selection
(c) reciprocal altruism
(d) selfish behavior
(e) altruistic behavior

2. Which of the following terms apply to a roommate who borrows your shampoo when she/he has run out, but will not allow you to borrow their shampoo when you need it?
(a) altruistic
(b) mutualist
(c) cheater
(d) a and c
(e) b and c

Further Readings

Reciprocal Altruism http://www.bbc.co.uk/nature/animals/mammals/explore/altruism.shtml

Reciprocal Altruism in Vampire Bats http://www.bio.davidson.edu/people/vecase/behavior/Spring2002/Perry/altruism.html

If you are interested in learning more about Evolutionary Psychology here is a link to a bunch of Frequently asked questions. Some of this goes into way more detail than we need to be worried about for this class.
FAQ Evolutionary Psychology http://www.anth.ucsb.edu/projects/human/evpsychfaq.html

Expected Learning Outcomes

By the end of this course a fully engaged student should be able to

- define reciprocal altruism
- discuss the conditions under which altruistic acts can be explained by reciprocal altruism
- examine an example of an altruistic behavior and determine whether reciprocal altruism is the best explanation
- explain how participants benefit by being involved in reciprodal altruism in real world examples (e.g, vampire bats)
- define a cheater in a reciprocal altruism system and discuss (a) why cheating is a problem in the system and (b) what organisms can do to reduce cheating
- discuss Trivers' ideas about how human psychology has been influenced by reciprocal altruism (be able to provide your opinion about Trivers' ideas and be able to back up your opinions)

Answers 1. c even though this is an example of altruistic behavior, the best explanation for this behavior is reciprocal altruism) 2. c

Patterns of Selection

2009-01-13T11:56:00.000-08:00

As I mentioned in class, I want you to understand the three patters on selection- directional selection, stabilizing selection, and disruptive selection. In addition, to the readings in your textbook, you will find useful info on this topic in the Encyclopedia of the Earth article on Evolution http://www.eoearth.org/article/Evolution.

Expected Learning Outcomes

By the end of this course, the fully engaged student should be able to

- distinguish between directional, stabilizing, and disruptive selection
- describes how directional. stabilizing, and disruptive selection work
- give examples of traits produced by each of these patterns of selection
- draw the graph that shows the relationship between fitness and trait size that produces each of these patterns of selection.

Altruism Part 2

2009-01-13T10:09:00.000-08:00

Question to Think About

Some birds have a behavior known as "helping at the nest". A female bird will sometimes help another bird rear offspring rather than laying her own eggs and raising them. There are two different hypothese to explain this behavior. First, this may be an example of an altruistic behavior that can be explained by kin selection. Alternatively, this may be an example of a purely selfish behavior. It is possible that young inexperienced birds are not very good at raising offspring the first time they try and by helping another bird to raise offspring they may get practice that makes them better at rearing offspring later on.

1) Explain how you as a scientist would conduct a study to distinguish between these two alternative hypothese.

2) Should a female bird who is capable of raising three offspring on her own help her sister to raise her sister's offspring if helping her sister allows her sister to raise five more offspring? Be sure that you would be able to explain to someone else how you determined your answer.

If you post your answers to the blog then I will be able to take a look at them and you can also get some feedback from fellow students.

Old Exam Questions

Here are some examples of old exam questions dealing with altruism. See if you can figure out the correct answers (answers provided at the bottom of this post).

Researchers studying black-tailed prairie dogs conducted an experiment where they dragged a stuffed badger (a predator of prairie dogs) across the colony. They repeated the experiment 698 times over the course of 3 years. The researchers observed that individuals with no offspring in the colony gave a warning call 19% of the time whereas individuals with offspring in the colony called almost 50% of the time. Which of the following could explain why individuals with no offspring would ever call?
(a) group selection
(b) other squirrels will return the favor in the future
(c) they have other relatives in the colony
(d) a and b
(e) a, b, or c would explain this observation

Which of the following are examples of an altruistic trait?
(a) an African wild dog sharing food with other members of the group
(b) a female choosing to mate with a symmetric male
(c) a sterile worker bee helping her sister (the queen) to reproduce
(d) a and c
(e) neither a, b, or c

Further Reading

Here are links to a couple of articles you might want ot take a look at-

Altruistic behaviors http://www.eoearth.org/article/Altruistic_behaviors

Kin selection http://www.eoearth.org/article/Kin_selection

More advanced reading

One of the problems with introductory courses is that we have to cover so many topics that it is not possible to go into very much detail over any of them. If you are interested in learning more about kin selection and altruism the following article would be good to look at.

Kin selection: fact and fiction. http://westgroup.biology.ed.ac.uk/pdf/Griffin&West_02.pdf

Answers to the test questions: 1) c 2) d

SI Schedule for BIOL 1404

2009-01-12T09:27:00.001-08:00

Jimmy Stickles will be leading SI session scheduled

Mondays 7:30 - 9:00 in room 109 in Holden Hall

Thursdays 7:30 - 9:00 in room 109 in Holden Hall

The first meeting will be Thursday January 15th.

Announcements about Lab

2009-01-10T09:14:00.000-08:00

Labs will begin on January 13th. All labs will meet on the week of January 20 - 23.

Before attending the first lab period:

1. Complete the Preliminary Exercise to Lab 1 (lab manual pp. 1-6). Be prepared to hand this in

2. Read Lab 1
a) Part I, Week 1 (pp. 7 - 11
b) Part II, Week 1 (pp. 17-21)
Be prepared for a reading quiz.

Altruism- Part 1

2009-01-08T14:06:00.000-08:00

From our discussion about natural selection you should have learned that organisms have the traits they do because traits that produce phenotypes that are more successful at transmitting genes to the next generation (surviving and reproducing) become more common in a population over time. Thus, we expect organisms to have traits that maximize their individual survival and reproduction (we call these selfish traits).

We should originally be a little bit confused when we learn about altruistic traits. How can genes that produce traits that decrease an organisms abilty to survive or reproduce become more common in a population?!? Luckily, we have learned that understanding what happens in natural selection requires us to focus on the transmission of genes. Apparently, organisms that behave altruistically are actually passing on more genes by behaving altruistically than they would by behaving selfishly. How can this be? (this problem perplexed Darwin).

Fortunately, a lot of really smart scientists have thought about altruism and have recognized that their are a variety of different ways that organisms behaving altruistically could pass on more genes than organisms acting selfishly. There are at least 4 different hypotheses that can explain the evolution of altruistic behaviors (one of these will probably only help to explain altruism in humans).

The first explanation for why organisms were altruistic was the idea of group selection. Group selection is the idea that organisms have traits becasue those traits "assure the survival of the species". At first glance this seems like a pretty useful idea, but it actually does not work and it has been a very difficult idea to remove from the minds of the general public even though scientists have know that it is wrong and unecessary (there are much better theories about the causes of altruism) for over forty years. It would take a while for me to explain why group selection doesn't work so I won't spend any more time talking about it either in class or here on the blog. However, if you are interested in learning more about this I would be happy to chat with you.

It is important for this class that you are able to understand under which conditions the other hypotheses could explain the presence of altruistic behaviors.

Hamilton's Rule

Hamilton's Rule is a mathematical equation that helps scientists understand under which conditions organisms should behave altruistically and when they should behave selfishly. It is important that you understand (1) how sceintists use mathematical models to help us understand the world and (2) what Hamilton's Rule tells us about when organisms should behave altruistically.

Suggested Readings

Biological Altruism- http://plato.stanford.edu/entries/altruism-biological/

Videos

Prairie dog giving a warning call - http://www.youtube.com/watch?v=rXCPaNWcTFo

Expected Learming Outcomes

By the end of the course a fully engaged students should be able to

1) define altruistic traits and provide several examples

2) compare and contrast selfish traits and altruistic traits

3) explain why altruistic traits at first glance appear to be difficult to understand based on what we know about the process of natural selection

4) discuss at least four possible hypotheses that explain the presence of altruistic traits and explain under which circumstances these theories are expected to apply

5) use “Hamilton’s Rule” as an example to illustrate how biologists use mathematical models to help them understand biology

6) discuss how Sherman’s work with Belding’s Ground Squirrels provided support for Hamilton’s Rule

7) be able to determine which hypothesis best helps you understand any examples of altruistic traits that I give you and be able to justify that answer

Natural Selection

2009-01-04T13:09:00.000-08:00

An understanding of the process of natural selection helps us to understand the amazing diversity of life on the earth.

Expected Learning Outcomes

By the end of the course a fully engaged students should be able to

1) define the process of natural selection

2) distinguish between the patterns of stabilizing, disruptive, and directional selection and provide examples of each pattern

3) describe how the process of natural selection has produced a trait that is an adaptation to a particular environmental condition.

4) explain why organisms are not expected to be perfectly adapted to their environments

5) discuss the conditions that would cause natural selection to stop

6) explain why natural selection is expected to produce selfish traits

Here is a link to a website from UC Berkeley that might be useful to take a look at-

http://evolution.berkeley.edu/evolibrary/article/evo_25

The Mark McGinley Story

2009-01-04T12:18:00.000-08:00

Here is the perfect cure for insomnia!

The Formative Years
I was born in Corpus Christi, TX and after a couple of moves we ended up in Rosenberg, (near Houston) where I attended grade school. I was interested in biology from an early age; I watched Marlin Perkins and Jacque Cousteau and I spent a lot of time outdoors on family camping and fishing trips. Even though I grew up near Houston during the Apollo years, I always thought that it would be much cooler to be a biologist than an astronaut.

When I was in the sixth grade my family moved to Australia for four years. This was an amazing life change for a kid who thought that the annual trip to my grandparents’ house in Oklahoma was a big deal. I had the incomparable experience of living in another country and experiencing a whole new way of life. Probably the biggest difference between Australia and the U.S. was the schools. I went to an all-boys English-style private school where we had to wear uniforms (suits and ties) and straw boater hats to class everyday (this probably explains my preferred style of dress today).

The move also provided me with the opportunity to travel the world. During trips through Europe and Asia we saw many places of historical and cultural interest. Among my favorites were the Coliseum in Rome, the Tower of London, and Mt. Fuji in Japan. More importantly, my travels exposed me to many new biological experiences including seeing hippos, gazelles, elephants, and a cheetah in South Africa, snorkeling and beachcombing in Hawaii, Tahiti, Fiji, and the Great Barrier Reef, chasing emus through the Australian outback, watching a male lyrebird do his mating dance, watching fairy penguins come ashore for the night off of the coast of southern Australia, and many sightings of other Australian wildlife including kangaroos and koalas (how many people do you know that have ever seen a koala running along the ground?).

During the summer before my sophomore year in high school we moved to Thousand Oaks, CA (old-timers will remember TO as the former summer home of the Dallas Cowboys before they were ruined by Jerry Jones) where I graduated from high school. During my senior year I spent a week studying ecology and philosophy in Yosemite National Park and this trip confirmed by desire to be a biologist.

Education
I enrolled at the University of California, Santa Barbara to study biology. UCSB is an incredible place to go to school (I could see the ocean from my bedroom window three out of the four years that I was there) and it also happened to have one of the best ecology programs in the world. Joe Connell (one of the most influential ecologist of our era) taught the ecology section of my intro biology course and also taught my first ecology course, so it is probably his fault that I am here today because after finishing his course I knew that I wanted to be an ecologist. Later, after taking courses from Steve Rothstein and Bob Warner, I became interested in behavioral and evolutionary ecology and I decided to go to grad school to study behavioral ecology. I went to Kansas State University in Manhattan, KS which was a pretty big change from UCSB. I enjoyed K-State (I learned to bleed purple for Wildcat basketball) and I was lucky to be able to spend summers working for my advisor Chris Smith at the Mountain Research Station in Colorado studying pollination in lodgepole pine. My Masters Thesis extended optimal foraging models to examine woodrats foraging for non-food items (sticks that they use to build their houses). I also did a theoretical study examining how food stress should affect sex ratios. I earned a Ph. D. at the University in Salt Lake City. For my Ph. D. thesis with Jon Seger, I developed models and conducted experiments to understand the causes of seed size variation in plants. During my little free time, I played volleyball with the U of U Volleyball Club team and I was probably the only person in the whole city who did not ski (I still don’t see the point of intentionally getting cold). I spent two years working as a post-doctoral researcher with Dave Tilman at the University of Minnesota. Our research focused on succession in old fields at Cedar Creek Natural History Area just north of Minneapolis.

Life at Texas Tech
I started as an Assistant Professor in the Department of Biological Sciences at Texas Tech University in 1991. I am currently an Associate Professor with a joint position in the Honors College and the Department of Biological Sciences. In the Honors College I work closely with the Natural History and Humanities degree (http://www.depts.ttu.edu/honors/nhh/)

Teaching
I teach a wide variety of classes at Tech. Two of my favorite courses are Tropical Marine Biology (taught in Jamaica and Belize) and the Rio Grande Class (we take a week-long canoe trip through Big Bend over Spring Break). For the past 6 summers I have worked as a scuba instructor and marine biologist with Odyssey Expeditions leading sailing and scuba trips through the Caribbean (British Virgin Islands, Martinique, St. Lucia, and St. Vincent & the Grenadines).

Scholarship
For several years I conducted ecological research in the sand shinnery oak community in West Texas. My current interests are in science curriculum development and environmental education. I serve as a member of the Stewardship Committee of the Environmental Information Coalition and as an Author and Topic Editor for the Encyclopedia of the Earth (http://www.eoearth.org/). In the Malaysian Bat Education Adventure we are using the ecology of Malaysian Bats as the focus of an integrated science curriculum for students in Kindergarten through 8th grade.

Traveling
I enjoy traveling and I have been able to explore my passion for scuba diving on dive trips in Texas (San Solomon Springs in Balmorhea and the Flower Garden Banks) throughout the Caribbean as well as Yap, Palau, Solomon Islands, Fiji, Indonesia, and Galapagos Islands. My favorite marine critters include hammerhead sharks, pygmy sea horses, and “the pea”.

BIOL 1404 Course Syllabus

2009-01-04T12:15:00.000-08:00

Syllabus
BIOLOGY II (for Life Science Majors)
BIOL 1404, SPRING 2008

Class Information
Section 001: MWF 9:00 a.m. in Biology LH100; Section 002: MWF 10:00 a.m. in Biology LH100.
Test period: Tu, 5:30-7:00 p.m.
Prerequisite: BIOL 1403.

1st half: Dr. Mark McGinley 2nd half: Dr. Michael Dini, rm. 007, 742- 2729
McClellan Hall rm. 215, 742-1828 ext 242 Of. Hrs: M-Th 11-11:30 or by appt.
Of. Hrs: MWF, 11-12, or by appt. Website: http://courses.ttu.edu/biol1404- mdini
Group Of. Hrs: M, 5:30-7, rm. tba Group Of. Hrs: T, 5:30-6:30, rm. 023
e-mail: mark.mcginley@ttu.edu e-mail: michael.dini@ttu.edu

Required materials:
1. Class Text: Biology, 7th ed., by Campbell & Reece (last semester in use)
2. Lab Text: Lab Manual for Biology II, by M. Dini
3. dissecting kit and 5-6 prs of examining gloves
4. H-iTT 2-way “clicker” device

1. COURSE OVERVIEW & GOALS

BIOL 1404 is the second semester of a rigorous, writing-intensive, two-semester course. It is offered only during the spring, and designed to prepare life science majors for upper-level courses in the life sciences. Whereas BIOL 1403 focuses on the particulars of cell biology, biochemistry, molecular biology, classical genetics, reproductive/developmental biology and evolutionary theory, BIOL 1404 focuses on organisms as they relate to other organisms and to their physical environments (ecology), biodiversity, as well as on plant and animal anatomy and physiology. Overall, the course aims to give you a strong foundation in the principles of biology, many of which you may not encounter again in future courses. The course is meant to introduce you to the way that scientists approach and solve problems leading to the construction of new knowledge. It is also our hope that the course will continue to give you an important handle in your attempt to understand the place and role of humans in the world and, perhaps, your particular place in it. Students enrolled in this course must have passed BIOL 1403, or its equivalent at another institution. Students on academic probation, or who received a "W" or an "F" the last time they took BIOL 1403 should immediately drop this course. This course satisfies the Natural Sciences Core Curriculum requirement.

2. EXPECTED LEARNING OUTCOMES AND METHODS FOR ASSESSING LEARNING OUTCOMES

A. Understand basic concepts of evolutionary ecology, general ecology, cellular energetics, plant water potential, biodiversity, animal anatomy & physiology. ASSESSED BY: scores earned on four unit tests and a cumulative final exam.
B. Enable students to understand, construct, and evaluate relationships in biological sciences, and enable students to understand the basis for building and testing theories. ASSESSED BY: pre-semester and mid-semester performance on laboratory science process skills test.
C. Develop skills in scientific writing. ASSESSED BY: scores on expository essays that are parts of the four unit tests, and by scores on draft & final versions of written lab reports.

3. ENROLLMENT & ATTENDANCE

You should be enrolled separately in a lecture section (001 or 002) and in a laboratory section (501-518). See Dr. Dini immediately if you have doubts about your enrollment. Regular attendance is critical for the success of BIOL 1404 students. Success in this course will require a good set of notes, hopefully written by yourself, and the critical reading of all assigned pages in the textbook, for there will be test questions on material that has not been covered in lecture. Class will often begin with verbal announcements that are not formally duplicated anywhere else. You are responsible for getting missed announcements from classmates. We consider more than two absences during the semester to be excessive. It does not matter why you are not present in lecture. The simple fact is that if you are not present, you will not learn the material as well as you otherwise would. During the 2nd half of the semester, class participation will be monitored using the H-iTT devices. Particularly important is your regular attendance in lab. You must attend the lab section in which you are enrolled. More than two unexcused absences from lab will result in the loss of ALL points connected with the laboratory portion of this course. Not only should you be in class at every class meeting, but you should be attentive as well. Talking, dozing, reading newspapers or listening to music during class are totally uncool and are not tolerated. Access to the Worldwide Web is important for success in this course.

4. EVALUATION

Your semester letter grade will be determined from the scores you earn on four unit tests (50%), on your laboratory work (31%), on the cumulative final exam (19%). The scores for this course are not curved. Letter grades will be determined by the number of raw points you earn (NOT the percentage), according to the following scale:

A = 712-800 B = 624-711 C = 536-623 D = 448-535 F < 448
(89-100%) (78-88%) (67-77%) (56-66%) (<56%)

The four unit tests are worth 100 points each; the cumulative final exam is worth 150 points. The distribution of the 250 points connected with your laboratory work will be explained at the first lab meeting. Computer-graded portions of tests will be composed of multiple-choice and matching questions. All tests (except the final exam) will also contain essays. A limited number of students may take an all-essay version instead by making a request, as per the professor’s instructions. No test scores will be dropped. There will be re-tests for Test #1 and Test #3. Only students who earn a 40% or higher on the original tests will have the option to take these re-tests, which will be administered one week later. The re-test score will replace the score on the original test, whether the re-test score is higher or lower.

Most of the points for each test (90-95%) will be drawn from material covered in class. Thus, a good set of notes will be of much assistance in learning the material. Hand-written notes (only!) can be used during the regular tests of the semester, but not during the final exam. Roughly 5-10% of each test will be drawn from material in the textbook or other assigned readings, but not covered in class. Unprofessionally made videotapes of our lectures will be available at the PASS Center (205 West Hall; hours M-Th 8-8, F 8-5) but you should be aware that equipment is subject to failure and to our inexperience; thus, videotapes for all lectures are not guaranteed. You may tape record lectures, but recordings may be used only to study biology unless you have our permission to use them for other purposes. Cellular phones, palm pilots, pagers, and beepers may not be used during tests, labs, or lectures. Computers may not be used during tests. You may be asked to leave if your devices disturb the class.

We will make an effort to design tests that challenge you to do more than regurgitate facts. Repetitious reading of textbook and notes as a sole means of studying will get you no better than a grade of "C" because tests will ask you to apply, integrate and evaluate information in situations which may be different from those covered in class. They will be tests of your understanding of the principles of biology, not solely tests of your ability to memorize and recall. Appendix F of the lab manual consists of tests administered during the past few years in BIOL 1404, along with the answer keys. You may find these tests helpful as you prepare for this semester's tests, but realize that no test items from these old tests will appear on your tests. Tests may include material covered in previous testing units. Students are invited to create and submit sample multiple-choice questions for potential inclusion into all tests. A review session will be held before each unit test, usually on Monday evenings from 5-6.

Tests will be on Tuesday evenings at 5:30 sharp (see schedule for dates) and will last 90 minutes. You must be prepared to present a photo ID (does not have to be a Tech ID) at all tests; failure to do so can result in the disqualification of your test. Also, bring two #2 pencils and a pen. We will provide scantron forms. Anyone entering the test after someone has completed the test and left the room will not be allowed to take that test. While tests are scheduled at a frequency of about once a month, the test period on Tuesday afternoons will often be used for optional activities such as discussions of current topics, enhancing study or test-taking skills, administering re-tests, going over old tests, working on sample test questions, etc. We strongly encourage you to be present for as many of these sessions as you can.

Not all lab instructors are equal. As a result, it may be necessary to normalize lab scores in certain lab sections at the end of the semester.
5. UNDERSTANDING EVALUATION

Evaluating student performance is a complex and difficult process. While students cannot be pigeonholed, they can be judged on the basis of their achievements. Effort is an important component of achievement, but we cannot accurately gauge your effort. We are limited to measuring achievement by the number of points you earn. Below are descriptions of typical "A" and "C" students in BIOL 1403/1404 modified from an article in The Teaching Professor, August/September 1993.

The "A" Student -- An Outstanding Student The "C" Student -- A Mediocre Student
Attendance: "A" students have virtually perfect Attendance: "C" students sometimes miss class. They
attendance. Their commitment to the class put other priorities ahead of academic work. In some
resembles that of the teacher. cases, their health or constant fatigue renders them
Preparation: "A" students are prepared for class. physically unable to keep up with the demands of
They always read the assigned pages. Their high-level performance.
attention to detail is such that they occasionally Preparation: "C" students prepare their assignments
catch the teacher in a mistake. consistently but in a perfunctory manner. Their work
Curiosity: "A" students show interest in the class may be sloppy or careless. At times, it is incomplete.
and in biology. They look up or dig out what Curiosity: "C" students' interests are limited to issues
they don't understand. They often ask inter- like "Do we have to know this for the test?" They
esting questions or make thoughtful comments. are most interested in coping or getting by. Their
Retention: "A" students have retentive minds. goal is to spend as little time as possible in lab or
They are able to connect past learning with the studying.
present. They bring a background with them to Retention: "C" students only memorized things for
class and they continually check new information tests in high school; thus, they bring little background against what they previously learned. to the class. They will probably take little from it
Attitude: "A" students have a winning attitude. because they still use the same poor study habits.
They have both the determination and the self- Attitude: "C" students are not visibly committed to the
discipline necessary for success. They show class. They participate without enthusiasm. Their
initiative. They do things they have not been body language often expresses boredom.
told to do.
Talent: "C" students vary enormously in talent. Some
Talent: "A" students have something special. It have exceptional ability, but show undeniable signs
may be exceptional insight and intelligence. It of poor self-discipline or bad attitudes. Others are
may be unusual creativity, organizational skills, diligent, but below-average in academic ability.
commitment -- or a combination thereof. These Results: "C" students obtain mediocre or inconsistent
gifts are evident to the teacher and usually to results on tests. They have some concept of what is
other students as well. going on, but clearly have not mastered the material.
Results: "A" students make high grades on tests --
usually the highest in the class. Their lab work is
a pleasure to read.

Grade Distributions for the last two BIOL 1404 Classes
spring 2006 spring 2007
A = 11.8 A = 5.3%
B = 44.9% B = 34.1%
C = 31.5% C = 40.7%
D = 9.9% D = 17.0%
F = 1.9% F = 2.9%
W = 5.3% W = 8.2%

NOTE: Letter grade proportions were calculated based on the number of students enrolled on the last day of class, whereas “W” proportions were figured according to students enrolled on the 12th day of class.

6. SUPPLEMENTAL INSTRUCTION

The P.A.S.S. Center will sponsor a program in Supplemental Instruction (SI) specifically for BIOL 1404 students. The student leader will attend all lectures this semester and will offer free instructional SI sessions at times and places to be announced. This is a superb opportunity to get help from a peer who is also an expert.

7. TEST GRIEVANCE PROCEDURES

During the week of Jan. 28-Feb. 1, fifteen randomly selected lab sections may elect a representative to the Biology Advisory Committee (BAC) following brief presentations by the candidates concerning their qualifications for the position. This committee of students will meet the Wednesday afternoon following each regular unit test and re-test in order to evaluate student comments/criticisms about test items and to forward their recommendations to the course instructors, who will take these recommendations under advisement. The qualifications to serve on the committee are that the student took BIOL 1403 at Texas Tech and received a "C" or better, and that the student be free Wednesdays from 4-5 p.m.

The BAC does not consider essay questions. If you disagree with the score awarded to an essay, then type a detailed presentation of your grievance, attach it to the original essay and submit it to the appropriate instructor for re-evaluation. Essays done in pencil or erasable ink will not be reconsidered. This must be done within one week of the return of the essays. Likewise, suspected errors in the filling in of any part of the scantron form must be brought to the proper instructors' attention within one week of the posting of scores. Please do not procrastinate; check the posted scores as soon as possible.

8. WITHDRAWAL FROM COURSE

Students who think they should withdraw from the course should be aware that this course is offered only once a year, during the spring semester. Withdrawal must take place before 5:00 on March 12. To withdraw, students go to room 103 in West Hall and complete the proper paperwork. You need not inform the instructor, but it is helpful if you inform your lab instructor and lab partners of your intention to withdraw. Failure to withdraw properly will result in the grade of “F.” Students who plan to take this course elsewhere and transfer the credits to Texas Tech must insure that the other institution’s course (a) is designated specifically for majors (not non-majors and not both), (b) has a 3-h laboratory component, and (c) is a course that treats most of the following principles of biology: basic ecology; biodiversity; plant anatomy/physiology, and animal anatomy/physiology.

9. OTHER RELEVANT INFORMATION

Dishonesty on exams, written work or connected with your attendance in lab or lecture will meet with the most serious consequences. Students are expected to be aware of, and abide by, the University's Honor code. Plagiarism on written lab reports or essays (copying/paraphrasing from other students or from other sources without giving due credit) will result in the loss of all points for that exercise, at the very least. Smoking and tobacco-chewing are not permitted in lecture or lab, nor is the use of cell phones, pagers, or beepers.

Disabling conditions: Any student who, because of a disabling condition (e.g. diabetes, epilepsy, dyslexia) may require special arrangements in order to meet course requirements should contact us as soon as possible so that accommodations can be made. Students should present appropriate verification from Disabled Student Services, Dean of Students Office. No requirement exists that accommodations be made prior to completion of this University procedure. Religious holidays: Any student who will miss tests because of recognized religious holidays should notify us as soon as possible so alternative arrangements can be made.

Can we talk? We can talk about anything you'd like. No appointment is necessary to see us during office hours -- just drop in. If office hours are not convenient, then feel free to make an appointment. You can also e-mail us; our e-mail addresses are on the front page of this syllabus. We should tell you that we are not happy to deliver all or part of a lecture to someone who has missed class.

10. SCHEDULING

WARNING- Some of the information about dates listed in this syllabus that I have posted on-line are incorrect. Thus, I have deleted that information from the blog. The information listed in the paper syllabus that I passed out in class are correct. This info can be found on-line at Dr. Dini's website http://courses.ttu.edu/biol1404-mdini/syllabus().htm

I am sorry for any inconvenience.