1. Clearly define and state the evolutionary significance of 5 of the following 6 terms (3 points each: Sum = 15).

Evolutionarily Significant Unit

Anisogamy

Inclusive fitness

Haldane's Rule

Spandrel

Antagonistic pleitropy

2. Clearly define and state the important distinction between the following concepts (6 points each: Sum=33)

Coevolution / Cospeciation

Homology / Homoplasy

Hymenoptera (ants, bees) / naked mole rats

3. The section reading provided some examples of how scientists can do experimental manipulations to test hypotheses of evolution. Describe the key manipulation that the experimenter used to examine the specific question presented in the following papers. (5 points each; sum = 48)

i) Bill Rice used Drosophila melanogaster to study questions relating to the evolution of sex.

ii) Resnick et al. used guppies to study the evolution of life histories (5 points; sum = 43)

iii) Mohamed Noor used Drosophila pseudoobscura to study reinforcement (5 points; sum = 48)

4. You are presented with two different species that show strong sexual dimorphism in secondary sexual characteristics: Horned beetles where males have exaggerated horns, compared to females; and peacocks where the males have bright, showy tail feathers compared to females. Which of these patterns is best explained by intersexual selection and which is best explained by intrasexual selection? Clearly explain why. (10 points; sum = 58)

5. Below are the phylogenies of five different groups of mammals living in an area that has experienced a lot of geological activity, splitting the area into different regions. The species are identified by letters (A, B, C…), and the region that they live in is represented by a number above the species ID. The map below shows the location of the regions with respect to one another (a circle with lines through it). Use the collective information that is provided by these five independent phylogenies (the congruence of cladograms) to answer the following questions. i) Identify the earliest vicariance event and justify your answer. ii) Identify any vicariance events whose relative timing (earlier vs. later) cannot be determined, and justify your answer, iii) Identify which taxon shows dispersal and justify your answer. (15 points; sum = 73)

Mice Rats Voles Squirrels Moles

Mice Rats Voles Squirrels Moles

1 2

3 4

1 2

3 4

6. Drosophila mojavensis and D. arizonensis live in the Southwestern United States and have been used as a species pair to study reproductive isolation. Flies of one sex and species are placed in an observation chamber with flies of the opposite sex from both species. The proportion of homotypic matings (between same species) and the proportion of heterotypic matings (between different species). are then recorded. In the table below, isolation indexes are listed for tests where the male and female mojavensis flies were collected from either a region of allopatry or a region where mojavensis is sympatric with arizonensis. Isolation is quantified by I = 1-(Proportion heterotypic/Proportion homotypic); i.e., higher number means stronger isolation.

Test:

mojavensis females x males of both species mojavensis males x females of both species

mojavensis flies from: mojavensis flies from:

Allopatry I = 0.28 Allopatry I = 0.73

Sympatry I = 0.89 Sympatry I = 0.94

i) Do these data support or reject the hypothesis that there is premating isolation in this species pair? Clearly justify your answer (5 points; sum = 78).

ii) Do these data support the hypothesis that there is reinforcement in this species pair? Clearly justify your answer (5 points; sum = 83).

iii) Would you conclude that there is postmating isolation in this species pair? Clearly justify your answer (5 points; sum = 88).

7. A "key innovation" is a novel trait that originates in a particular group and affords that group specific evolutionary "advantages", such as increased rates of speciation often referred to as "adaptive radiations". The columbines (genus Aquilegia) are flower species with a characteristic morphological trait known as a nectar spur (see diagram). A molecular systematic analysis demonstrated that all species of columbines are very closely related as evidenced by a high degree of genetic similarity despite the fact that different species of columbines have very distinct morphologies and live in very different regions of the world (see phylogeny below). These data suggest that the nectar spur is a "key innovation". However, the tree shown lacks crucial information that might lead one to conclude that the nectar spur had a causal role in the presumed adaptive radiation. Recently, new DNA sequence data were obtained for Semiaquilegia, a relative of Aquilegia, that does not have nectar spurs. On the tree below draw a branch that places Semiaquilegia in the position that most clearly supports the notion that nectar spurs are a key innovation. Your placement of this new branch in the tree should take into account both 1) cladistic information (which species are the sister group to Semiaquilegia) and 2) branch length information (where along the length of existing branches the new branch splits off). Note that the small numbers above the branches of the tree indicate the number of character changes along that branch, and the numbers below the branch represent the bootstrap percentage indicating the statistical certainty of that branch.

Clearly justify your placement of the new branch in terms of these two issues. (12 points; sum = 100)