Readings: Chapters 7-8 from “Endless Forms Most Beautiful”
With ideas you encounter in the reading, develop three discussion questions that integrate, explore, and extend what we have learned so far in the course about the mechanisms and principles of development. Access the link to the discussion question submission on the course schedule. If they are well thought out and complete they will earn you part of your credit for the homework assignment that day. We will select a couple of these to discuss in class (without associating names with who submitted them).
Reading Questions--bring your answers to these questions, as you will be responsible for answering one of them in class. You will not turn these answers in.
1. How does duplication of structures/functional redundancy create opportunities for specialization?
2. What evidence suggest that insect wings and crustacean respiratory lobes are homologous? How convincing is this evidence to you? Why?
3. Why have snakes lost their forelimbs? What alterations in the genome do you think caused the changes you propose in your answer?
4. Where are the mutational changes that have led to the loss of spines (hindlimbs) in the stickleback (in a short 10,000yr period of time)?
5. What type of mutational changes most likely occurred to cause the suppression of wing formation by abdominal segments in insects? In your answer consider wing formation genes, Hox genes, and the DNA sequences (enhancers/switches) controlling wing formation gene expression or Hox gene expression.
6. How has the modularity of animals been significant in the evolution of animal form?
7. In what way is the pattern of a butterfly wing similar to the pattern along the anterior posterior axis of the Drosophila embryo?
8. How is the expression of distal-less modified to participate in eye spot development in butterfly wings?