Evolution of animal form: potential meets selection

Readings: Chapter 9-10 from “Endless Forms Most Beautiful”

Informational Questions (bring your answers to these questions, as you will be responsible for answering one of them at the start of class):

1. In what ways is the mutant form of the MC1R protein found in black jaguars similar to the oncogenic form of Ras?

2. Is MC1R a tool kit protein? Explain your reasoning.

3. What is fitness and how does it impact allele frequency in a population?

4. Does the lack of a coat color pattern in nature (for example all white) mean that there is not a developmental process to generate it?

5. Did all of the changes in morphology that make humans different from their ancestors occur at the same time and rate? What does this imply about the genetic changes underlying human evolution?

6. How similar is our genome to the chimpanzee genome? How many differences in the genome are there?

7. What type of genetic variation likely leads to difference in form between humans and chimpanzees?

8. In light of what we have discussed in EFMB, how plausible is the premise of “Rise of the Planet of the Apes” (2011 science fiction movie)? The premise is that administration of a virus (they can carry 10-15 genes) leads to the “humanization” of a chimpanzee so that it can acquire language, advanced cognitive skills, and speech.

Discussion Questions (we will consider these questions in class after talking about the Informational Question above) as a way to apply and explore the ideas presented in the reading.

9. (Group 1) How convincing is the identification of the toolkit in all animals as evidence that animals (including us) are descendants of a common ancestor?

10. (Group 2) What aspect of the genome/DNA (switches or toolkit genes) do you think contain the instructions for building animal form? How are the instructions changed during evolution?

11. (Group 3) What do you think would happen to the form of an embryo if (a) a signature sequence, (b) a switch, or (c) the protein coding sequence of a toolkit gene were deleted from the genome? Why?