Thursday, April 23, 2009

Final Exam

This final exam is due on May 6th. Please email it to be at

Each of these questions is worth 20 points. I expect that it should be possible to provide an excellant answer to each of these questins in less than two pages double spaced (per question). You may use the Ecology Reader, any notes you have, or any other source of information to help you prepare this exam (besides another class member). Please let me know if you have any questions.

Question 1. (20 points)

How would you respond if one of your student's parents asked you "Why should my students learn about evolution"?

Question 2. (20 points)

Why is exponential growth an unrealistic pattern for most species?

Question 3. (20 points)

List the major interspecific interactions that occur in a community? discuss the role that these interactions can occur in influencing population and community characteristics.

Question 4. (20 points)

Define natural selection. Why is this process important to biologists?

Question 5. (20 points)

Define, compare and contrast energy flow and nutrient cycling. (because of the difficulty in putting diagrams in Microsoft Word, you should be able to answer this question without using diagrams).

Final Assignment

I am afraid that I am badly overscheduled this semester and that combined with being sick for a while has caused me to be unexcusably far behind. I realized that I failed to write down the due date of your writing assignment in my schedule so you think that you have an assignment due soon that has not yet been assigned. I apologize for the inconveience.

First, the writing assignment due on the 25th is cancelled.

Second, your final exam for the course will be due on May 6th *not May 2nd as it says on the syllabus)

Third, becasue of the lack of writing assignment, your grades will be calculated as follows. I will calculate grades three ways and you will earn the highest grade.

Midterm Exam 30%
Cumulative Final Exam 70%


Midterm Exam 60%
Cumulative Final Exam 40%


Midterm Exam 50%
Cumulative Final Exam 50%

Tuesday, March 24, 2009

Evidence for Evolution

I think that it is important to be able to explain to students that scientists do not support evolution because they are anti-religious but rather because the theory of evolution helps us to understand every facet of biology. Here is a link to a powerpoint presentation that outlines some of the strongest lines of evidence in support of evolution.

How I Introduce Evolution to My Students at Tech

My training is in ecology, with a emphasis in the field of evolutionary ecology, so it is really not possible for me to talk about biology without using an evolutionary framework. As you might be remember, I started out this class by talking about “natural selection”- microevolution.

I have no idea what the exact figures are, but I know that the majority of my students come to Tech not-believing in evolution because of what they have learned from the pastors and parents while growing up.

When I teach evolution, I am simply trying to teach students the background theory that will help them make sense of the biological world. In the same way that I thought that understanding how scientists use mathematical models such as the Lotka-volterra model of competition to understand communities, I think that it is imperative that students studying biology have a strong foundation in evolutionary theory. Thus, I am not trying to “convert” anyone or to challenge their religious beliefs. I do however find it interesting that I am more likely to challenge people’s religious beliefs when talking about evolution than I am when talking about competition models. We should spend some time talking about why that is.

I always start by talking about science. Science is a way of learning about the world. Other ways of learning about the world include philosophy and religion.

Science is differentiated from alternative ways of learning about the world by
1) what it studies
2) how it studies it

(a) Science deals with the natural world and assumes that the world is governed by “natural laws” (I don’t spend too much time worrying about where these laws came from, I just accept that they exist)and (b) science only studies things that can be observed

Religion, on the other hane deals with the supernatural so science simply can’t study it.

Scientists learn about the world using the scientific method. Scientists use observations and experiments to test predictions of hypotheses. Thus, data determines “truth” in science. Religious truth often relies on “revelations” not data.

Thus, science and religion differ on what they can study and how they study it.
Here is the critical question- which way of learning about the world is best? Any particular method is not the best, they are complementary ways of learning about the world and each works best within its intended boundaries. Science has nothing to say about religion, faith, or God.

My suggestion is that if you want to study observable phenomena that take place in the natural world then science is the best approach. We spend our lives surrounded by the applied knowledge that comes from using the process of science.

Think about a couple of examples

1) you come out in the morning and you can’t start your car.

Possible hypotheses
- you left your lights on and the battery has gone dead
- something is wrong with the starter

Where do these hypotheses come from? The knowledge that engines run according the laws of physics and chemistry helps us to understand how they work

Alternative hypotheses
-you ran over a fairy on the way home last night and they are punishing you
-your neighbor is a witch and has put a hex on your car because your dog barks too much

We are likely to laugh at these alternative hypotheses because we understand the mechanical basis of car problems. Who do you take your car to for repairs- (i) Gus the mechanic (who whether he knows it or not uses his knowledge of physics and chemistry to diagnose what is wrong and repair your car) or (ii) Princess Fatima the Gypsy around the corner? Obviously, we choose Gus.

2) What do you do if you get sick?

The most obvious answer is that you go to the Doctor and do what they tell you. Certainly you might ask people to pray for you or pray for yourself. Some religions (e.g., Christian Scientists) rely on spiritual healing alone and will not take their children to the doctor when they are sick. I doubt that most people around here would support that position.

Here is a great quote from Einstein- “The whole of science is nothing more than a refinement of everyday thinking.”

In my introductory Biology class I discuss the evolution of plants. Never have I had a student have problems with green algae giving rise to mosses, mosses evolving into ferns etc. The problem arises when we start talking about human origins. Humans descended from apes- monkeys are ancestors.

Why this is is difficult for me to understand- it appears that we are in the middle of a culture war. From an exhibit in the Institute of Creation Research Museum we learn that (i) Creationism gives us True Faith, True Morality, True Hope, True Americanism, True Family Life and (ii) Evolutionism gives us Communism, Naziism, Atheism, Slavery, Racism, Pornography, Genocide, Abortion, Infanticide , Homosexuality, Child Abuse, Bestiality. This goes back to William Jennings Bryan’s ideas of evolution causing a loss of morals. I don't understand this point of view, but clearly this is the way that many people think which is why they are willing to fight so hard to get creation in and evolution out.

I think that students should be encouraged to think about how they use the different ways of learning about the world. When do they use science, when do they use religion? What do they do when the two are in conflict? How do they justify using science to study the world expect for when it conflicts with their religious beliefs (why doesn’t science work then?). Each person needs to draw their own conclusion about these issues. However, I think that it is extremely important that we not allow people to push their “religious agendas” into the science classroom.

Creationism and Intelligent Design

We are now reaching what is usually the most difficult part of this course- talking about evolution. Because Lubbock is located near the buckle of the Bible Belt, this topic is always controversial with my students here at Tech (including past Multidisplinary Science Masters Degree students). If we were meeting in a face to face setting then you would hopefully know me well enough to conclude that I am not an evil person (and if you concluded that I was evil, it would be for a better reason than believing in evolution). Obviously, the teaching of evolution in Texas schools continues to be controversial and it remains to be seen what the revised TEKS will be like. Because my understanding of the process of evolution is the most powerful tool that I have in my biological toolbag I think it is critical that you learn why I think that evolution is such a powerful tool for helping us to learn about biology. My goal is not to be controversial or step on anyone's toes and I hope that we will be able to have good discussions about this topic.

Creationism and Intelligent Design

In his book “Tower of Babel The Evidence Against the New Creationism”, Robert Pennock reviews the various types of Creationists.

“Wild-type” Creationist

God dictated the bible word for word so we must take it literally. From Genesis we know (i)God created the world from nothing in 6 days, 6000 years ago and (ii) God destroyed the world with a great flood, all current people and animals are descendents of Noah’s Arc.

There are different views of Creationism today which arises out of biblical interpretation

Most creationists consider themselves as Evangelicals
- Biblical inerrancy- can be understood in different ways
- Bible is the revealed word of God- so every word is true
- plenary verbal inspiration- Biblical writers directed by God but used own style
- inspired concepts- written down by people over time

Young Earth Creationism

Bible is meant to be taken literally on all matters of faith and the real world

-creation took 6 24 hour days
-Adam formed directly from the dust on the ground and Eve from Adam’s rib
- Jonah was literally swallowed and lived in the Belly by as great fish

1- sudden creation of the universe, energy, and life out of nothing
2- the insufficiency of mutation and natural selection in bringing about the development of all living kinds from a single organism
3- changes only within fixed limits of originally created species
4- separate ancestry of humans and apes
5- explanation of earths geology by catastrophism including a worldwide flood
6- A relatively recent inception of earth and living kinds

Dated by readings of ancestry in the Bible- 6000 to 10,000 years

Young Earth Creationists include-
1)Institute for Creation Research- San Diego - Duane Gish, Henry Morris and his son
2)Answers in Geneis- Kentucky-Ken Ham and Gary Parker
3)Center for Scientific Creationism- Phoenix

Old Earth Creationism

-still consider biblical inerrancy, just don’t read the bible literally

Days are not 24 hour human days, but are God-sized days
Others apply gap interpretation- gaps between Genesis 1:1 and 1:2
Days are “actual days” but they are not consecutive

There is a big battle between the Young Earth Creationists and the Old Earth Creationists

Progressive Creationism

Accepts much of the scientific picture of development of the universe, assuming for the most part that it developed according to natural laws.
- God intervened at strategic points along the way

Theistic Evolutionism

Theists who accept Darwinian evolution. Basically view God as a creator- started physical laws etc.

Evolutionary creationism

God directly guided the process of evolution

Intelligent-Design Creationism

Many ID proponents hold advanced degrees and positions in universities

Phillip Johnson- UC Berkely Law school
Michael Behe- Biochemist,Lehigh University Biology Department

Johnson’s view
1. personal creator
2. supernatural
3. initiated
4. continues to control the process of creation
5. in the furtherance of some end or purpose

“irreducible complexity”- some systems are complex and can only work if the entire system is in place
-therefore there is no way that they could be formed by gradual steps because there is no way that earlier versions could have been selected for

Interesting idea, but again I don’t see that it is science (even worse it doesn’t help us get anywhere- can’t make any predictions or lead to new avenues of study)

Is there a controversy between evolution and creationism?

1) Scientific controversy?

No- evolution remains the cornerstone upon which everything in biology makes sense. No “real biologist” that I know thinks that there is a problem. I know of no creation scientists or ID proponents that do not admit to being Christian and that that is a important part of why they feel as they do (I at least respect that most of these ID scientist are up front about their religious beliefs)

Theistic science- “The Bible is the ultimate scientific approach” This approach would fundamentally change the way that we approach science and the scientific community has certainly not seen the need for this.

2) Religious controversy?

The debate is often framed as being between scientists and fundamental creationists
-not necessarily the case because many mainstream Christian denominations have no trouble with evolution

-thus there may be a religious controversy between different Christian beliefs

3) Philosophical controversy?
Evolution/creation debate often linked to Gallileo and Church debate

Battle between the truth of nature and the nature of truth

Creationists have tried to use ID as a wedge to show that people are either for the religious position or against it- there is no middle ground.
-The Bible is either inerrant or worthless
-Christianity or atheism
-Certainty or sketpticism
-Absolute morality or subjectivism (relativism)

Many philosophers would argue that these issues are not so black or white.

4) Political controversy?

Controversy is a struggle for power
- whichever side gets the most votes should be the side that wins
- science be damned??

Brief History of Creationism

Modern History began with the Scopes “Monkey Trial” in 1925. The ACLU orchestrated a challenge of the Tenessee state law that banned the teaching of evolution. The trial was one of the first famous trials fought in the media featuring Clarence Darrow vs William Jennings Bryan. Bryan thought that American society was undergoing moral decay that he blamed on scientific materialism as exemplified by evolution were making people question biblical authority.

Even though Bryan officially won his case (Scopes was fined $100) the general public generally agreed that evolution had won (Bryan tried to defend the Genesis version of creation on the stand and was torn apart by Darrow).

Textbook publishers were uninterested in controversy so they basically excluded evolution from biology books up until the end of the 1950s.

In the 60s the sputnik scare revitalized American Science teaching – BSCS curriculum contained evolution.

In 1973 Tenesee passed a law saying that anyone who taught evolution also had to teach the Genesis account. In 1975 this law was found unconstitutional because it was blatantly including religion

Over the next several years creationists passed laws in several states requiring the teaching of “creation science”

1982 case in Arkansas challenged a law requiring the teaching of creation science. The case brought in experts on evolution, thermodynamics and geology also experts on religion to answer the question-was creation science really science?

Judge Overton defined science as “what scientists do” and “what is accepted by the scientific community”. He dentified the “essential characteristics” of science (based on the ideals of the philosopher of science Michael Ruse)

1. It is guided by natural law
2. It has to be explanatory by reference to natural law
3. It is testable against the empirical world
4. Its conclusions are tentative; i.e., the are not necessarily the final word
5. It is falsifiable

Overton ruled that creation science fails to meet the essential characteristics and was thus not science. From religious testimony he ruled that creation science was religious so the law violated the establishment clause.

2004 Georgia case

Required placement of sticker on biology books as “a theory not a fact”
Judge ordered the stickers removed

2004 ID case- Dover Pennsylvania

The policy required students to hear a statement about intelligent design before ninth-grade lessons on evolution. The statement said Darwin’s theory is “not a fact” and has inexplicable “gaps.” It referred students to an intelligent-design textbook, “Of Pandas and People.” (which turns out to be a creationist book that basically had the words “creation” replaced by the words “intelligent design”.)
Judge Jones, a Republican and a churchgoer appointed to the federal bench three years ago. decried the “breathtaking inanity” of the Dover policy and accused several board members of lying to conceal their true motive, which he said was to promote religion. A six-week trial over the issue yielded “overwhelming evidence” establishing that intelligent design “is a religious view, a mere re-labeling of creationism, and not a scientific theory”

ID “may be true, a proposition on which the court takes no position, ID is not science.” Among other things, he said intelligent design “violates the centuries-old ground rules of science by invoking and permitting supernatural causation”; it relies on “flawed and illogical” arguments; and its attacks on evolution “have been refuted by the scientific community.”

How do Creationists and proponents of Intelligent design attempt to attack evolution?

The IDers (and other creationists) often take these approaches to get their message across

1) Try to refute evolution
Set up a false dichotomy that there are two possible explanations for the origin of the life either by evolution or created by the Judeo-Christian God. They try to show weaknesses in evolution and then having shown that evolution is wrong we are forced to accept their view of creationism. However, here are many other possible creation stories than Genesis.

2) Equal time approaches
There are two valid scientific alternatives so it is only fair to present both ideas. This doesn’t work for two reasons- (i) there are not only two alternative (Australian aboriginals and Mayans have their own creation stories)and (ii) hese other approaches are not science because they inherently bring in a supernatural creator.

3) Force of Numbers

IDers from the Discovery Instute presented a petition showing that 400 scientists dissented from Darwinism- took them 4 years to get this many signatures. 128 signees were Biologists and virtually none of them conducted research that had anything to do with the subject (the one signatory I know from Tech is an Electrical Engineer).

Some scientists responded with The Four Day Petition, whose name A Scientific Support For Darwinism is an allegorical reference to the Discovery Institute's A Scientific Dissent From Darwinism, a petition that took four years to generate just over 400 signatories. This project, The Four Day Petition, ran from Sept 28th , 2005 to October 1st , 2005. R. Joe organized the Four Day Petition with no outside funding or professional society’s assistance and generated 7,732 verified signatories of concerned scientists, all by word of mouth (well e-mail actually). Of those signatories 6,965 are US residents including 4066 with a PhD.
“My genuine thanks to the thousands of you who felt strongly enough about this petitions statement to make the time during those four days to pass the word onto your personal network of peers. The response to your efforts was tremendous. Your efforts resulted in a response 1809% higher than the Discovery Institutes at a rate 697,000% faster. It is also interesting to note that the Discovery Institute budget is $4,000,000 a year while mine is, well non existent J These results are not bad my friends, not bad at all.”

4) Because Creationists have repeatedly had their ideas judged to be a religious they have tried to argue that evolution is really a “secular religion”

5) The Kansas Board of Education has taken a couple of clever strategies. They eliminated evolution from the state science standards. Teachers remain free to teach it, but won’t be tested on it which basically eliminates it from the curriculum. When in 1999, the board eliminated most references to evolution, a move Harvard paleontologist Stephen Jay Gould said was akin to teaching "American history without Lincoln."

The Kansas School Board then tried a new approach and rewrote the definition of science, so that it is no longer limited to the search for natural explanations of phenomena.

No wonder - "The 10 Worst Jobs in Science," as listed by Popular Science magazine, October 2005: #3 is Biology teacher in Kansas


Hello Everyone,

I have returned from Malaysia and Big Bend so I guess that it is time to get back to work. Visiting Malaysia was an incredible experience. I spent about a week at Krau Wildlife Reserve working with researchers studying bat ecology. I have never seen a true rainforest before and I have to admit that after a week I still couldn't see the trees for the forest. We would to out every night and morning to check the trap for bats. The bats were really cool (some of them had bodies that was smaller than my thumb). I spent a day in Kuala Lumpur meeting with folks at the University of Malaya which was interesting. Canoeing down the Rio Grande through Big Bend was an ideal way to spend my spring break. Taking a group of interested students out in the field is obviously the best way to learn so I was a little embarassed this morning when I needed to meet with them in a room using Powerpoint.

Obviously, I am extremely far behind. I will try to take a serious look at all of your midterms by the end of the weekend and get back to you with feedback. After I take a look at the midterms I will have a better idea exactly what I would like you to do as a final project. I will have more info for you next week.

Thursday, February 19, 2009

Invasive Species

Our understanding of most of the current environmental issues facing us would probably be improved with a stronger understanding of basic ecology. Environmental issues, such as invasive species, provide opportunities to apply what we have learned in an applied context.

Invasive species can have profound effects on an environment. Because the resident species have had no evolutionary history with the invader it is possible that the resident species are highly susceptible to the negative effects of an invader (e.g., they have no defenses agaist a predator or a disease). Last summer I saw first hand how evolutionary history can influence interactions bewteen species. The Galapagos Islands are so isolated from continental South America that no large predators have been able to colonize the archipelago. Thus, when we would go hiking on the Galapagos Islands, the birds and animals living there literally showed no fear so that we were able to approach them very closely (I used to be impressed at all of the amazing photos I have seen of birds on the Galapagos Islands, but now I know that the photographer was only two feet away). Imagine what would have happened had a predator been introduced; the fearless animals would have been easy prey to an exotic predator.

Further Info

1) Here is a link to a presentation that I made for my seminar on the Rio Grande River. It provides general information about invasive species, how species can harm communities, and efforts that people have used to try to control invasive species. It also discusses some examples of species that have invaded Texas.

2) Here is a link to a presentation that I made for my seminar on the Rio Grande River discussing the invasive tree, tamarisk (Salt Cedar). Tamarisk is an important invasive species in riparian areas of the western US and has become an important environmental issue in the region. There is a lot more detail in this presentation than you need to worry about.

Expected Learning Outcomes

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

- discuss the variety of mechanism through which novel species are introduced into a community (TEKS 112.43. 12B & 12E and TEKS 112.44. 4C, 4D, & 4E)

- identity examples of introduced species in your own area

- identify examples where introduced species have caused economic and environmental damage to an ecosystem (TEKS 112.43. 12B & 12E and TEKS 112.44. 4C, 4D, & 4E)

- explain why introduced species might often have large negative effects in communities (TEKS 112.43. 12B & 12E and TEKS 112.44. 4C, 4D, & 4E)

- discuss potential ways to limit invasions or to remove novel species (TEKS 112.43. 12B & 12E and TEKS 112.44. 4C, 4D, & 4E)