Fun With Graphs- Quiz Yourself

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

Fun With Graphs- Logistic Growth

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 we need to cover in this class (it is definitely more complex than you need to be able to explain to your students).

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

Fun With Graphs- Exponential Growth

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. It 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

This section on population ecology is the topic that I am most concerned about teaching via distance. It seems easier to show you in person how I work problems than it is to try to explain in writing how to work the problems. In addition, I have always found it easier to teach math and graphing when I can give students some problems to solve and I can walk around the classroom peering over their shoulders while they work (it is fun to freak out freshmen that way!).

After you are comfortable with the paremeters that I introduced in teh Population Ecology I. blog, then I would read the articles from the EoE in the following order.

Population ecology
Exponential growth
Logistic growth
Carrying Capacity
Intraspecific competition

These articles (which I have written) attemtp to introduce the readers to the two most important mathematical models that have been used to describe simple population growth.

Exponential Growth

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 varies over time.

(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 describ 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.

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


Final Thoughts

Many students find using math to think about biological concepts and using graphs to illustrate pattersn to be difficult. It is probably difficult for students because they have not had very much practice doing it. If you are comfortable using math and graphs, then most of what we are doing will not be too difficult. However, if you lack a lot of experience using math and graphs, this section might be a bit frustrating. My advice to you is to keep plugging away. Once you learn how to approach these problems, then you will find that you have developed a skill that you can use over an over again. It will, however, require some practice to develop these skills. Please let me know if you are having any problems or questions. You can post on the blog, send me an email, or if you think it will help to actually talk, then we can talk over the phone (it is frustratingly difficult to quickly and easily show you graphs electronically). I need to go educate the masses of Texas Tech, but I will be back on-line soon to talk about logistic growth (a more realistic and useful model of population growth).

Population Ecology I. Basic Parameters

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?

Adaptations to Desert Environments

Selection Thinking

The true power of the process of natural selection is that it provides us way of thinking about the diversity in the world around us. If we expect that organisms will be adapted to the condition in their environment the we can think like engineers and ask the questions- how would I design the a trait in that environment? We call this approach "selection thinking". This approach has been highly successful in allowing scientists to understand aspects of physiology, morphology, life history, and behavior in all sorts of environments in all sorts of species. In my research I have used this approach to study behavior in sparrows, woodrats, and beavers and reproduction in deer and plants.

Often, ecologists use mathematical models (often models ripped off from economists and engineers) as tools to help them understand traits of organisms. Although explicitly using mathematical models to study adaptations is probably too advanced for most middle school and high school science classes, I do think that it is important for you as teachers to know that math is an extremely important tool for scientists and be able to express that to your students as often as possible. It is unfortunate that math and science are usually taught as separate topics. As a Zoology Major at UCSB I took calculus during my Freshman year because that is what my advisor told me to do. During the final quarter of my senior year when in a graduate level Reproductive Ecology the professor used calculus to solve a problem that I had the "Oh, now I understand why I was supposed to learn all of that math!" moment.

Using mathematical models forces scientists to do very important things. First, we must clearly state our assumption. Second, it forces us to formailze out logic. When scientists don't use mathetical models they are often forced to rely upon what we call "arm waving" verbal arguments (you should be familiar with these arguments because we see them all of the time when we watch politicians on TV). Often, conclusions that seem reasonable based on verbal arguments actually are incorrect because they are based on either unrealistic assumptions or faulty logic.

I came across an example of a faulty verbal argument while I was working on my Ph.D. I was interested in understanding how parents should invest resources to their offspring, specifically, how big should plants make their seeds. This is a relatively simple problem to think about. When plants reproduce they should be selected to make as many surviving offspring as possible. The number of surviving offspring should be the product of the number of seeds produced and the probability that a seedling survives after it germinates. The number of seeds produced depends on seed size; you can make fewer larger seeds or more smaller seeds. Because the size of a seed is influenced by how many resources that seed contains, the probability that a seedling survives is positively correlated with the size of the seed. The original models predicted that fitness would be maximized if a maternal plant made all of here seeds exactly the same size. However, when you actually measure sizes of individual seeds (and I measured tens of thousands of seeds during my Ph. D.) you see that there is a lot of variation in the size of seeds produced by the same plant. The focus of my Ph.D. research was to try to figure out why plants produced seeds of different sizes.

Several years earlier a scientist named Dan Janzen (a very famous tropical biologist) had published a theory suggesting that producing different sized seeds was an adaptation. His theory was based on a "hand-waving" verbal arguement. In a class I took in graduate school I developed a model to try to see if Janzen's arguement really made sense. My model suggested that Janzen's conclusions were wrong because the verbal logic he used was faulty. My professor suggested that I tried to publish my model. While I was writing that paper, another professor from Orgegon published a matehmatical model that came up with the completely different conclusions than my model. When I compared our two models, I saw that his conclusions were based on an unrealistic assumption and when you used the correct assumption in his model we drew similar conclusions.

Selection Thinking in Arid Environments

Because the environmental conditions in arid environments are particualarly severe, deserts offer an interesting location to study adaptations to local environmental conditions. Hopefully, the readings will give you a broad exposure to how natural selection can mold physiology, morpology, reproduction, and behavior in arid environments.

Powerpoint Presentation

Click here to see a powerpoint presentation "Introduction to Desert Flora and Fauna"
http://www.slideshare.net/secret/pw2UrKumkR7KRT

Expected Learning Outcomes

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

- identify and discuss the unique challenges associated with living in arid environments (TEKS 112.43 12C)
- explain adaptations of animals and plants for water uptake and water conservation (TEKS 112.43. 7B)
- explain adaptations of animals and plants for dealing with high temperatures (TEKS 112.43. 7B
- develop curricular materials to teach students about adaptations to arid environments TEKS 112.43. 7B)
- develop curricular materials to teach how animals or plants are adapted to a different (non-desert) environment ((TEKS 112.43. 7B & 112.43.12B)

Practice Assignment

To test your understanding of how natural selection affects traits, I suggest that you try to develop a lesson to teach your students how the traits that you observe depends on the environmental conditions. In about one page, outline the lesson you would use to explain how and why the same trait varies between two very different environments. I suggest that you choose an adaptation to life in the desert and compare that train in an very different environment such as a tropical rainforest (much wetter) or the arctic (much colder). If you post your answers here I, and hopefully your classmates, will provide you some feedback.

Natural Selection

The EoE article on Natural Selection (that I wrote) is still under review, so I will give you a copy of the info in that article here. The Evolution article in the EoE has some useful information about natural selection as well.

Natural Selection

Biologists are interested in understanding the amazing diversity of life that we observe around us. Fortunately, we have the process of natural selection to aid us with this task.

It is my experience that most people have a poor understanding of how natural selection works, so it might be useful to briefly discuss how natural selection can cause organisms to become adapted to their environment. First, natural selection is not best defined as “survival of the fittest” (it is a shame that the one thing that apparently every student remembers from school is wrong). Instead, natural selection is best defined as a process.

Natural selection is a process where if-

1) there is variation in traits among individuals in a population,

2) this variation in traits is heritable (i.e., there is a resemblance in traits between parents and offspring), and

3) this variation in traits affects survival, fecundity (the number of babies produced), or mating ability,

then the trait frequency varies between the parent and offspring generation.

Variation in traits among individuals in a population can occur because different organisms have different genes or because they are found in different environments. Genes are molecules (deoxyribose nucleic acids, DNA) that are found in chromosomes. Genes play an important role in determining phenotypes because (1) genes influence which proteins are produced inside cells, (2) proteins can act as enzymes or “biological catalysts” (catalysts act by speeding up the rate of chemical reactions), and (3) phenotypes are influenced by which chemical reactions are taking place in the cells. Thus, if two individuals have different genes then they can produce different proteins that act differently as enzymes. Differences in enzymes leads to differences in the types, or rates, of chemical reactions occurring in the cell which can produce distinctly different phenotypes.

Genes also cause traits to be heritable. We tend to resemble our parents because we receive genes from both of our parents. We are not exactly like our parents because we only get half of our genes from our Mom and the other half from our Dad. When organisms reproduce sexually they produce gametes (eggs – female gametes, sperm- male gametes) by the process of meiosis. The male gamete is mobile (usually sperm are able to swim) so they move to the egg where fertilization occurs to produce a zygote. Crossing over of chromosomes during meiosis and the random combination of gametes during fertilization results in the production of offspring that are genetically different from both of their parents and all of their siblings.

Genes get passed on from one generation to the next by reproduction. Obviously, genes that produce traits that allow organisms to be good at surviving and reproducing should get passed on more often than genes that produce traits that make organism bad at surviving or reproducing. Thus, over time we would expect genes that produce traits that make organisms better at surviving and reproducing to become more common in the population (this is what is meant by the change in trait frequency over time in the definition of natural selection). We might expect that these genes would get more and more common until all individuals in the population have these genes (the gene is “fixed” in the population). If this occurred there would be no more heritable phenotypic variation (assumptions 1 and 2 would not be met) so natural selection would cease.

The creation of new genetic variation by mutation will be needed for natural selection to continue. Mutations are changes in the genes (that typically occur as the result of mistakes produced during replication of chromosomes or the production of gametes) that lead to changes in the phenotypes. Mutations are random. If a mutation occurs that causes an individual to have higher survival or reproductive success, then we would expect the frequency of that gene to increase in the population. A sequence of selection followed by the introduction of new mutations repeated over time should produce organisms that are good at surviving and reproducing in their environments. We call traits that make organisms good at surviving and reproducing “adaptations”. We expect that over time, natural selection should cause organisms to be adapted to their environments.

Because conditions vary between different environments, it is not surprising that the traits that maximize survival and reproduction in differ between different environments. Because of the differences in environmental characteristics of aquatic and terrestrial environments, it is not at all surprising that we see very different types of organisms living in the water and on land.

Expected Learning Outcomes

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

- explain how the process of natural selection has produced a trait that has increased an organism's survival or reproduction in a particular environment (TEKS 112.43. 7B).

- identify and describe behavioral, physiological, and morphological adaptations to a particular environment (TEKS 112.43. 7B).

- develop curricular materials to teach students how and why the traits of similar organisms can be different across different environments (TEKS 112.43. 7B & 12C).

The Physical Environment- Quiz Yourself

I was sitting in my office looking at a globe (a common activity for me in Lubbock-- always planning my next trip) and I decided that I should test your learning so far. After you have gone through all of the reading material and thought about the factors that influence global patterns in you should be able to answer these questions. These questions are intended purely as a vehicle for making you think about the material a bit more, to allow you to test your understanding, and to hopefully stimulate some interaction. Your answers will not be graded in any way. If you like you can just answer them to yourself at home or you could post your answers as comments on the blog so that you can get feedback from your fellow classmates and me and so you can see how other students answered the questions (I hope you will choose this option).

Here are a few questions in honor of standardized multiple choice tests. (you should be able to write out a sentence or two to justify your answers)

1. What is the predominant direction that the winds blow in Adelaide, Australia (approximately 37 deegrees South latitude)?
a) north
b) south
c) east
d) west

2. What is the predominant direction that the winds blow in Runaway Bay, Jamaica (approximately 19 degrees North latitude)?
a) north
b) south
c) east
d) west

3. What is the predominant direction that the winds blow in Reykyvic, Iceland (approximately 64 degrees North latitude)?
a) north
b) south
c) east
d) west

4. Peru is located on the west coast of South America. What is the predominant direction of ocean currents along Peru?
a) north to south
b) south to north
c) east to west
d) west to east

5. Portland, Oregon and Pierre, South Dakota are located at approximately the same latitude (about 45 degrees north) but they have very different climates. Use your understanding of the the factors that affect climate of a region to discuss how and why the climate varies between these two regions.

6. Finally, we have spent a lot of time trying to understand the factors that determine global patterns of temperature and precipitation. What would you tell your students to explain to them why it is so imporant to know what the temperature and precipitation of an area is if you want to understand the biology of an area?

Science Education: I'd like your input

I thought that I would let you know a little about some of the things that I am working on and I would like to ask you for some input.

I started my research career conducting ecological research. Most of my research has been theoretical in nature and I have only done it because I want to know the answers. More recently I have recognized that there are many issues whose solution would benefit from a “scientifically literate” general public (and science is cool!!). There are lots of really creative scientists conducting interesting research now, but I don’t think that there are as many people (at the university level) working to make science more understandable and interesting to the general public. Thus, over the last few years I have become much more interested in environmental education and science curriculum development.

I (in collaboration with two of my biology department colleagues) am currently working on a project we call the Malaysian Bat Education Adventure. Our goal is to use the ecology of Malaysian rainforest bats as the focus of an integrated science curriculum from K – 8th grade. The logic behind this plan is that too often science concepts are taught in small disconnected bites that lack any common context. By developing an integrated learning progression focused on the ecology of bats (bats are pretty cool) we hope to help students understand important science concepts better. In less than two weeks we will start testing some of our ideas by having 4th and 5th grade teachers at a Lubbock elementary school try using our curriculum. We hope to finish up a website containing this information in the next week or so and I will send you the link when it is finished to get your critique.

Recently, a number of us from science, math, and education departments received a big grant to develop a Masters Degree that attempts to integrate math and science for Middle School Teachers. We were successful in obtaining this grant largely because of the success of the Multidiscplinary Science Masters program you are involved with.

I have enjoyed thinking about how I would teach science to 4th graders and middle school students. When my fellow professors and I get together for our weekly beverage session, the conversation often turns to our frustrations about our students’ weaknesses. For example, some things that frustrate me are that too many college students (1) have such a hard time making and interpreting graphs and (2) don’t know how to write the scientific name (Genus name first letter capitalized, species name all lower case and the whole name italicized or underlined). Some of these weaknesses are simple and could easily be introduced to early grades and then be reinforced as the students progress through their science career.

Our goal is not to criticize the teachers that come before us (it is always depressing to hear my colleagues complain about something that their students don’t understand and then realize that “I taught them that in Intro Biology”). However, it has been helpful for us to think about what would be important skills for students to develop early in their science education so that they would be comfortable working with them by the time the reach college.

All of this is a prelude into asking for input. I am sure that you have similar conversations about your students with your colleagues. What knowledge, skills, attitudes, etc. would you like your students to have when they arrive in your classes? What suggestions do you have about how science education could be improved? How could your students performance be improved by changes in their education in other fields (math, English, etc.)? What can we do to try to increase communication among science teachers at different levels and among teachers of different subjects at the same level? Let me know what you think.

The Physical Environment

Note- We are experiencing the joys of working with material that can dynamically be added and removed from a website. A general article, "Climate" has been removed from the site since I prepared the reader last fall (so don't waste too much time worrying about that).


Introduction

The physical environment can have a profound influence on ecology at a variety of levels. For example, the physical environment can act as a strong selective presssure to produce adaptations or can influence the rates of nutrient cycling through an ecosystem. For our simple purposes here, the two most important components of the physical environment are temperature and precipitation. I suggest that we can predict a lot about what is going on ecologically in an environment if we know something about temperature and precipitation patterns.

From watching the nightly news we all know how difficult it is for the local weatherperson to accurately predict what the weather is going to be like tomorrow. Fortunately, it is much easier to understand broad patterns of variation in temperature and precipitation.

Temperature



The dominant global temperature pattern is that it tends to get cooler as you move away from the poles. The cause of this is relatively simple. Because the earth is so far from the sun, the light rays hitting the earth are basically paralell to each other. Because of the curvature of the earth, sunlight hitting the earth near the equator falls over a smaller area than sunlight hitting near the poles. Because the same amount of light energy is hitting a smaller area near the equator, the concentration of energy/area is greater near the equator than the pole thus resulting in higher temperatures.


Elevation is another factor that influences global temperatures. Because there is less insulating atmosphere above areas of high elevation temperatures tend to decrease as you go up in elevation.

Large bodies of water can mediate temperature variations. For example, seasonal and daily variation in temperatures are much lower in areas near the ocean (maritime climates) than they are in areas far from the ocean (continental climates).

Global temperature patterns can also be affected by patterns of ocean circulation. For example, the west coast of continents are often cooled by cool water flowing from the poles to the tropics while the east coasts of continents can be warmed by warmer water from the tropics to the poles (e.g., the Gulf Stream). If you have ever been to the beach in southern California you surely noticed how cold the water was; east coast beaches at similar latitudes have much warmer water.

Precipitation

In order to understand global precipitation patterns you need to understand global patterns of atmospheric circulation. Hopefully, after studying the article on atmospheric circulation you will be able to explain-

1. why there tends to be high precipitation in tropical regions and

2. why precipitation tends to be low at 30 degrees North and South of the equator.



Patterns of precipitation can also be influenced by the presence of mountains. As air masses containing moisture hit a mountain they are forced upward. Because rising air cools and cool air







holds less moisture, precipitation occurs on the windward side of mountains. Once the air mass has passed over the mountain in falls to lower elevations and gets warmer. Because most of the moisture has been lost as precipitation on the windward side of the mountain and the warmer air holds more moisture there is very little precipitation on the leward side of the mountain resulting in a "rainshadow desert".



Let's think about Lubbock!

Let's see if we can use our newfound understanding of some of the factors influencing temperature and precipitation to make predictions about what the climate should be like in Lubbock. What information do we need about the geographic location of Lubbock to help us understand the climate? First, we need to know the latitude; Lubbock is located approximately 33 degrees north. Second we need to know something about the proximity to the ocean. As an old beach boy, I can guarantee you that we are a long, long way from the ocean in Lubbock. Third, where is Lubbock in relation to mountains? Lubbock is located to the east of the southern extension of the Rockies.

Why is all of this important?

1. What can we learn from the latitude of 33 degrees North? This latitude is still close enough to the equator to be warm so we expect relatively high temperatures. Because Lubbock lies near the 30 degree zone of low precipitation we would predict relatively low precipitation. At 30 degrees North we would predict that Lubbock would receive predominately winds from the west.

2. From the continental location of Lubbock we would predict fairly extreme daily and seasonal fluctuations of temperatures.

3. Because Lubbock lies in the Westerlies most of the precipitation that is arriving in Lubbock comes from the Pacific Ocean. Because these winds have passed over the Rockies we would predict that Lubbock would lie in a rainshadow, again causing low precipitation.

How did we do. If anyone has ever been in Lubbock (especially in the spring time) you would know that the wind almost always blows in from the west. Temperatures are relatively warm but there is fairly large seasonal and daily variations in temperature. Lubbock has a semi-arid climate and receives on average about 18 inches of precipitation per year. Thus, with just a little bit of knowlege about the factors that influence global patterns of temperature and precipitation we were able to fairly accurately the climate in Lubbock. Thus, I would expect that organisms native to Lubbock should be well adapted to the low precipitation, continental climate of the region (the short grass prairie was the dominant vegetation type presettlement).

See use these patterns to understand climate in your town (note climate patterns in Texas are complicated in central and eastern Texas becasue of the influence of air masses coming up from the Gulf). Compare the temperature and precipitation of your town with that if very divergent locations around the globe.


Further Reading

If you would like some more detailed information about factors affecting climate and the atmosphere you can check out the Atmosphere Chapter in Michael Pidwirny's online Physical Geography textbook http://www.physicalgeography.net/fundamentals/contents.html.

Powerpoint Presentation

Click here to see the powerpoint presentation "Factors Influencing the Physical Environment"
http://www.slideshare.net/secret/EaVq4nm5KuSsBI

Expected Learning Outcomes

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

- describe global patterns of variation in temperature and precipitation and be able to explain the causes of these patterns (TEKS 112.49. 13B).

- develop curricular material to teach students how to understand the causes of their local climate and how and why the local climate differs from the climate found in other locations around the earth (TEKS 112.49. 13B).

The Mark McGinley Story

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”.

Course Syllabus

Ecology and Evolution for Teachers BIOL 5311
Spring 2009
Course Syllabus

Instructor

Dr. Mark McGinley
Associate Professor
Honors College and Department of Biological Sciences
Room 215 McClelland Hall
742-1828 ext. 242
mark.mcginley@ttu.edu

Contacting Me
The best way for you to contact me during this course is via email (I spend much of my life attached to my computer and I am usually pretty good at getting back to people via email). I am also happy to chat with you on the phone. If you would like to chat on the phone send me an email and we can set up an appointment for a time for us to talk by phone). We should also be able to communicate via the course blog.

Note: I will be traveling out of town during the middle portion of the semester. I will be traveling to Malaysia from February 25 – March 11th and I will be on a field trip on the Rio Grande River from March 13 – 20 so I will not be able to communicate with you during those times.

Course Outline
The purpose of this course is to provide a content knowledge in the fields of ecology and evolution to practicing teachers. The ecology portion of this course will examine ecology of individuals, populations, and communities and introduce you to the techniques that ecologists use to develop hypotheses (including mathematical modeling) and test their hypotheses in the lab and the field. The evolution portion of the course will discuss the apparent controversy between science and religion and discuss topics of micro and macro evolution.

Required Readings.
There is no textbook required for this class. The readings for the ecology portion of this course will come from this class will come from the Ecology for Teachers Reader published in the Encyclopedia of the Earth.

Course Blog
I have created a blog for this course (my initial effort at blogging). The Ecology for Teachers blog can be found at http://ecologyforteachers.blogspot.com/. This blog will offer a means of communication among all members of this course. I will post regularly (at least weekly) on this site and I encourage you to use this as a forum for interaction. I am not going to grade your participation in the blog, but obviously the more that you share your thoughts on the blog, the better indication I will have about how the class is going.

Expected Learning Outcomes
Explicit expected learning outcomes for each lesson are located in the Ecology for Teachers Reader on the EoE.

Methods for Assessing the Expected Learning Outcomes
The expected learning outcomes will be assessed using a midterm exam, a final exam, and a project. Students in this class will be involved in the Student Science Communication Project with the EoE. You will be required to write an article suitable for publication by the EoE. All articles that meet my approval will be submitted for review by the EoE and articles that are accepted by the Topic Editor will be published. More details of this assignment will be coming.

Grading
Midterm Exam (Due February 21st) 30%
Cumulative Final Exam (due May 2nd) 40%
Term Paper (due April 25th) 30%

Because it is not always possible for me to make the grades fall on a 90, 80, 70, etc. scale, I will let you know the grade that your score would have earned after each assignment. This course is not graded on a curve, so it is possible for all, or no, students to earn a particular grade.


Course Outline

Week 1. Jan 7 - 10 The Physical Environment (Ecology For Teachers Reader- EoE)

Week 2. Jan 12 - 16 The Evolutionary Context (Ecology For Teachers Reader- EoE)
Hierarchical Organization of Ecology- Individual Traits (Ecology For Teachers Reader- EoE)

Week 3. Jan 19 - 23 Hierarchical Organization of Ecology – Population Ecology (Ecology For Teachers Reader- EoE)

Week 4. Jan 26 - 30 Hierarchical Organization of Ecology- Community Ecology- Competition, Predation, Mutualism (Ecology For Teachers Reader- EoE)

Week 5. Feb 2 - 6 Hierarchical Organization of Ecology- Community Ecology- Food Webs, Indirect Effects (Ecology For Teachers Reader- EoE)

Week 6. Feb 9 - 13 Hierarchical Organization of Ecology- Ecosystem Ecology (Ecology For Teachers Reader- EoE)

Week 7. Feb 16 - 20 Hierarchical Organization of Ecology – Landscape Ecology, Biomes, and Biosphere (Ecology For Teachers Reader- EoE)
Take Home Midterm Due February 21st by 5:00 PM Submit via email

Week 8. Feb 23 - 27 Biodiversity (Ecology For Teachers Reader- EoE)

I will be traveling to Malaysia from February 25 – March 11th and I will be on a field trip on the Rio Grande River from March 13 – 20.

Week 9 March 2 - 6 Environmental Issues- Invasive Species (Ecology For Teachers Reader- EoE)

Week 10. March 9 - 13 Work on Projects

Week 11. March 16 – 20 Spring Break

Week 12. March 23 – 27 Creation, Intelligent Design, and Evolution

Week 13 March 30 – April 3 Scientific Evidence for Evolution
Powerpoint presentation “Evidence for Evolution”

Week 14. April 6 – 10 Microevolution

Adaptation by natural selection by Dr. McGinley

http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_25
http://evolution.berkeley.edu/evolibrary/search/topicbrowse2.php?topic_id=53

Week 15. April 13 – 18. Macroevolution
Understanding Evolution- Speciation (University of California, Berkeley) http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_40
Powerpoint presentation “Models of Speciation and Macroevolution” “Species Concepts and Speciation”

Week 16. April 20 – 28 Final Thoughts

Final Exam Due May 2nd

TEKS
Chapter 112. Texas Essential Knowledge and Skills for ScienceSubchapter C. High School
112.43. Biology.
(7) Science concepts. The student knows the theory of biological evolution. The student is expected to:
(A) identify evidence of change in species using fossils, DNA sequences, anatomical similarities, physiological similarities, and embryology; and
(B) illustrate the results of natural selection in speciation, diversity, phylogeny, adaptation, behavior, and extinction.
(9) Science concepts. The student knows metabolic processes and energy transfers that occur in living organisms. The student is expected to:
(D) analyze the flow of matter and energy through different trophic levels and between organisms and the physical environment.
(11) Science concepts. The student knows that organisms maintain homeostasis. The student is expected to:
(A) identify and describe the relationships between internal feedback mechanisms in the maintenance of homeostasis;
(B) investigate and identify how organisms, including humans, respond to external stimuli;
(D) summarize the role of microorganisms in maintaining and disrupting equilibrium including diseases in plants and animals and decay in an ecosystem.
(12) Science concepts. The student knows that interdependence and interactions occur within an ecosystem. The student is expected to:
(A) analyze the flow of energy through various cycles including the carbon, oxygen, nitrogen, and water cycles;
(B) interpret interactions among organisms exhibiting predation, parasitism, commensalism, and mutualism;
(C) compare variations, tolerances, and adaptations of plants and animals in different biomes;
(D) identify and illustrate that long-term survival of species is dependent on a resource base that may be limited; and
(E) investigate and explain the interactions in an ecosystem including food chains, food webs, and food pyramids.

§112.44. Environmental Systems.
(4) Science concepts. The student knows the relationships of biotic and abiotic factors within habitats, ecosystems, and biomes. The student is expected to:
(A) identify indigenous plants and animals, assess their role within an ecosystem, and compare them to plants and animals in other ecosystems and biomes;
(B) make observations and compile data about fluctuations in abiotic cycles and evaluate the effects of abiotic factors on local ecosystems and biomes;
(C) evaluate the impact of human activity such as methods of pest control, hydroponics, organic gardening, or farming on ecosystems;
(D) predict how the introduction, removal, or reintroduction of an organism may alter the food chain and affect existing populations; and
(E) predict changes that may occur in an ecosystem if biodiversity is increased or reduced.
(5) Science concepts. The student knows the interrelationships among the resources within the local environmental system. The student is expected to:
(A) summarize methods of land use and management;
(B) identify source, use, quality, and conservation of water;
(C) document the use and conservation of both renewable and non-renewable resources;
(D) identify renewable and non-renewable resources that must come from outside an ecosystem such as food, water, lumber, and energy;
(E) analyze and evaluate the economic significance and interdependence of components of the environmental system; and
(F) evaluate the impact of human activity and technology on land fertility and aquatic viability.
(6) Science concepts. The student knows the sources and flow of energy through an environmental system. The student is expected to:
(A) summarize forms and sources of energy;
(B) explain the flow of energy in an ecosystem;
(C) investigate and explain the effects of energy transformations within an ecosystem; and
(D) investigate and identify energy interactions in an ecosystem.
(7) Science concepts. The student knows the relationship between carrying capacity and changes in populations and ecosystems. The student is expected to:
(A) relate carrying capacity to population dynamics;
(B) calculate exponential growth of populations;
(C) evaluate the depletion of non-renewable resources and propose alternatives; and
(D) analyze and make predictions about the impact on populations of geographic locales, natural events, diseases, and birth and death rates.
(8) Science concepts. The student knows that environments change. The student is expected to:
(A) analyze and describe the effects on environments of events such as fires, hurricanes, deforestation, mining, population growth, and municipal development;
(B) explain how regional changes in the environment may have a global effect;
(C) describe how communities have restored an ecosystem; and
(D) examine and describe a habitat restoration or protection program.

Welcome and Introduction

Welcome to Ecology and Evolution for Teachers (BIOL 5311)! By now you are all veterans of the Multidisciplinary Science Masters Program. I am excited to be teaching this course because I believe that improving science education is an important issue facing Texas and the USA today. I hope that this course will play a positive role towards meeting that goal.

This is the first time that I have taught this course via distance education (in fact, this is the first time that I have taught any course without face to face contact with students). Although I much prefer to teach in person, I am excited about the challenge of teaching a distance education course. Let me try to give you some ideas about how this course will work.

My Plan for This Course

Required Readings
For the last two years I have been working with the Earth Portal project run by the National Council of Science and Environment and Boston University (http://www.earthportal.org/). I currently serve as a member of the Stewardship Committee of the Environmental Information Coalition, the body that oversees the Earth Portal. The goal of the Earth Portal is to become the largest reliable information resource on the environment in history. The Encyclopedia of the Earth (EoE- http://www.eoearth.org/) is a critical component of the Earth Portal. I serve as an author and topic editor for the EoE and I am currently co-editing the Ecology Collection. The goal of the Ecology Collection is to provide access to the basic information in Ecology required to understand environmental issues.

The required readings for the Ecology portion of this course will come from the EoE. They will either be articles that have been written by scholars from around the world or taken from an AP Environmental Science Textbook that is posted on the EoE (http://www.eoearth.org/wiki/Draft:AP_Environmental_Science_%28course%29). To find readings for this course go to the EoE (http://www.eoearth.org/) and search for Ecology for Teachers Reader.

The required information for the Evolution portion of the course will be available online (websites from the University of California, Berkeley and University of Utah among others) and from Powerpoint presentations that I have developed.

The course syllabus will identify the readings from the EoE that cover the topics assigned for the week. At the end of each section is a list of expected learning outcomes for the material Note that I expect that you will have a high enough understanding of the material that you will be able to effectively teach the material to your students.

Course assignments
Obviously, I will need to assess your mastery of the material. There will be one midterm exam (due February 21st) and a final exam (due May 2nd). These exams will test how well you have mastered the expected learning outcomes for the course. In addition, you will participate in the Student Science Communication Project
(http://www.eoearth.org/wiki/Student_Science_Communication_Project). You will be able to research a topic and write an article/articles suitable for the EoE. If I approve your article, the I will submit it for review by the EoE and if your article is approved by a Topic Editor your article will be published for everyone in the world to see!!!!

Interaction
The best part of teaching face to face is that it is easy for us to communicate. I imagine that you have all had the experience of being halfway through your brilliantly-prepared presentation when you look at the students’ faces and realize that none of them have a clue about what you are talking about. Similarly, I am sure that you have your presentations interrupted by questions from students that either helped to clarify the material for them and their classmates or opened up new interesting areas to talk about. We won’t be able to share these opportunities in this class. Thus, in hopes of allowing for valuable teacher-student and student-student interaction I have developed a blog. I encourage you to post answers to questions that I ask on the blog, comment on the answers of your classmates, ask questions, or any other clever ways that you can think of you use the blog (this is new territory for me so I am up for suggestions about how to make this course as interactive as possible). You are also encouraged to contact me via email or via phone with any questions or comments that you have.

Suggestions
Here is how I would approach this material.
1) Preview the expected learning outcomes
2) Read all of the reading material
3) See if you can meet the expected learning outcomes
-if you would like to check your level of understanding you can write out answers and submit them via email for me to take a look at.
4) answer the questions posted on the blog (I highly encourage all of you to post your answers online).
5) ask questions
You can ask me questions via email or the phone
You can ask me and your fellow students questions on the blog