the adaptationist approach zol 313 may 22, 2008. the adaptationist approach zol 313 may 22, 2008...

The Adaptationist Approach

ZOL 313

May 22, 2008

The Adaptationist Approach

ZOL 313

May 22, 2008

Objectives:

1. Be able to define an adaptation and identify adaptive behaviors.

2. Become familiar with some different ways to test adaptationist hypotheses.

3. Understand why adaptations are not perfect.

4. Understand the concept of inclusive fitness and be able to calculate when it using Hamilton’s Rule

Moller 1994 - Fig. 4.4

- Fig. 6.15

What is an adaptation?

Fitness:

Example:

The “adaptationist approach” to studying animal behavior involves

How can we test adaptive hypotheses?

1.Experiments

2.Comparative Method

3.Optimality Theory

4.Game thoery

1.Using experiments to test adaptive hypotheses

Example:

Hypothesis 1:

Prediction:

1. Using experiments to test adaptive hypotheses

Hypothesis 2:

  Prediction b:

Prediction c:

Prediction a:

1. Using experiments to test adaptive hypotheses

Hypothesis 3:

Prediction a:

1. Using experiments to test adaptive hypotheses

Hypothesis 3:

1. Using experiments to test adaptive hypotheses

Prediction b:

2. Using the comparative method to test adaptive hypotheses

Example:

2. Using the comparative method to test adaptive hypotheses

Convergent evolution: Divergent evolution:

3. Using Optimality Theory to test adaptive hypotheses

3. Using Optimality Theory to test adaptive hypotheses

Example:

Benefit

Cost

4. Using Game Theory to test adaptive hypotheses

Why aren’t adaptations perfect?

1.Lack of genetic variation/appropriate mutations

2.Tradeoffs with other traits/pleiotropy

3.Coevolution

Why aren’t adaptations perfect? 1. Lack of genetic variation/appropriate mutations

Example:

Example:

Pleiotropy:

Example:

Why aren’t adaptations perfect? 2. Tradeoffs/pleiotropy

Example:

http://youtube.com/watch?v=mzTcmE-pMLU

Example: The “Farm Fox Experiment”

After many generations, their farm foxes also became more “dog-like” in: 1.

2.

Why aren’t adaptations perfect? 2. Tradeoffs/pleiotropy

"Well, in our country," said Alice, still panting a little, "You'd generally get to somewhere else--if you ran very fast for a long time as we've been doing."

"A slow sort of country!" said the Queen. "Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that."

Why aren’t adaptations perfect? 3. Coevolution

Example:The “ Hypothesis”

Why help others when you could help yourself?

Inclusive Fitness

Inclusive fitness=

In order for a behavior to be adaptive…

R=

Inclusive Fitness

Example: An inexperienced bird breeding on her own will produce an average of 1 offspring. If she helps her parents breed instead, she will help them raise an average of 2 more of her siblings than they would have without her help.

Should she help??? R= B= C=

Hamilton’s Rule:

22

Inclusive Fitness

Example: