1. According to the biological species concept, what is a species? Why do some biologists define species in this way?(1 pt)
2. Use the genetic-distance matrix that follows to establish the taxonomic relationships between the species listed. (Hint: Draw a phylogenetic tree to illustrate these taxonomic relationships.) (1 pt)
A B C D
B 4.8 —
C 0.7 5.0 —
D 3.6 4.7 3.6 —
3. What is the difference between ancestral traits and derived traits? Why is it important to make this distinction? (2 pts)
4. Chimpanzees and gorillas more closely resemble each other anatomically than either resembles humans. For example, the hands of chimpanzees and gorillas are structurally similar and quite different from human hands. Genetic-distance data suggest, however, that humans and chimpanzees are more closely related to each other than either is to gorillas. Assuming that the genetic-distance data are correct, give two explanations for the observed anatomical similarity between chimpanzees and gorillas. (2 pts)
5. Primates are considered to have “slow” life histories relative to mammals of a similar size. What primate qualities characterize this slow life history? What in the environment is related to having fast vs. slow life histories? Why is a large brain and a dependence on learning related to a slow life history? (1 pt)
6. What are the four taxa (phylogenetic groups/branches) of descending size that humans are a part of within the order of primates? Describe at least one defining characteristic of each. For three of the taxa, name what branch they separate from. (1 pt)
7. The Hardy-Weinberg Equilibrium is written as: 1 = (p2 + 2pq + q2). Please define each of the four terms in the equation (1, p2, 2pq, q2); what does each represent? (2 points)
