1. Briefly define and state the significance of following terms (3 points each ·= 15)

Minimum Viable Population Size

Reinforcement

Norm of Reaction

Homeotic Mutation

Runaway Sexual Selection

2. Clearly define each of the following concepts, and state the important distinction between them (6 points each ·= 33).

Grade / Clade

Coevolution / Cospeciation

Peripatric Speciation / Parapatric Speciation

3. Two incipient species of butterflies are currently in secondary contact after a period of geographic isolation. Natural hybridization occurs between the two forms in the wild, and hybrids of both sex have reduced fitness. An evolutionary geneticist has identified two genes, the choice locus which affects premating isolation, and the egglay locus which affects the viability of eggs laid by females (a postmating isolating factor). Both loci exhibit a number of different alleles (i.e. are polymorphic in both "species"). As evolution proceeds in this zone of hybridization, which locus will experience the greater evolutionary response? Briefly and Clearly explain why. (10 points ·= 43)

4. How could sexual selection play a role in speciation? Which species concept would be most applicable to analyzing the relationship between sexual selection and speciation? Briefly explain both (10 points ·= 53)

5. You are interested in the phylogeny of a groups of gulls and terns (OK, you used to be interested in...) and have various options regarding the rooting of the tree. You have collected new data on two outgroup species, bird X and bird Y that are neither tern nor gull, and can root the tree two ways: 1) with the outgroup as paraphyletic with respect to the ingroup, or 2) with the outgroup as a monophyletic sister group with respect to the ingroup. On the two trees below, a) draw in the branches that correspond to these two scenarios (1 and 2 above), and b) explain which of the two rooting scenarios provides more information about the ancestral character states of the ingroup. (8 points; ·= 61)

6. In the evolution of hominids (from Australopithecus to Homo habilis to Homo erectus to Homo sapiens), data suggest a positive interspecific allometry for body weight (X) and brain weight (Y) of adults, but each species exhibits a negative ontogenetic allometry for these same two traits. i) Label the axes, ii) plot four points for the adult forms of these species that illustrate the positive interspecific allometry (and draw the line through these points), iii) draw separate lines for each species that illustrates the negative ontogenetic allometry (it should end with the adult point; don't worry about actual values, just get the slopes right), and then iii) clearly describe what shape change occurs with increasing body size in the ontogenetic and the interspecific patterns of allometry. (12 points; ·= 73)

7. Life history theory seeks to explain the trade-off between traits affecting reproduction and survivorship. Reznick and co-workers transplanted guppies from a site where the main predator preyed on adult guppies (control site) to a site where a different predator preyed primarily on juvenile guppies (experimental site). After a number of years they examined several characteristics of the guppy population at the experimental site for changes in life history traits. For the traits listed below, state whether Reznick et al. observed an increase, a decrease or no change of the experimental population relative to the control. Provide short, well reasoned explanations for the evolutionary responses that are consistent with life history theory as it applies to survivorship and reproduction. Observation (12 points; ·= 85)

8. Peter Parasite is studying the tapeworms that live in the guts of cetaceans. He has sequenced a homologous region of DNA from each of six species of tapeworms found in different species of whales and obtained the DNA characters below. He has also determined the presence or absence (i.e., "distribution") of these six species of tapeworms in four different whale species "hosts" (B = Blue, F = Fin, G = Gray, H = Humpback; presence = +, absence = -). Pete has also discovered that the odd numbered worms are restricted to whale stomachs, while even numbered worms are restricted to intestines. Pete suspects that speciation in whales has been an important factor in the historical biogeography of tapeworms and believes that the phylogeny and distribution of the tapeworms will suggest a pattern of speciation in the whale hosts. From the data provided below (and ONLY these data) solve or answer the following:

i) Determine the phylogeny of the tapeworm species using parsimony, draw the cladogram and clearly indicate on your cladogram which characters and character states define monophyletic groups (you may assume that "Worm One" is the outgroup) (5 Points).

ii) From the information in the tapeworm cladogram, draw a cladogram of the whales that accurately reflects the history of vicariance events for tapeworms (5 Points).

iii) What is the most parsimonious explanation for the current distribution of these six species of tapeworms in the four whales? (5 Points) (15 Points total; ·= 100).

Species _____DNA Characters______Distribution in Whales

Alternate problem 6. The existence of exaggerated male traits, such as long sword-like extensions of the tail in male Xiphophorus fishes, is generally accounted for by sexual selection. The traditional view of sexual selection is that female preference for a male trait coevolves with the male trait itself. An alternative model of sexual selection, the "sensory drive hypothesis", argues that females evolve a sensory bias for a specific male trait that drives the subsequent origin and evolution of the trait. The following studies have been conducted: A) In species of Xiphophorus where males do not have swords (S- fish), females preferred males whose tails had been artificially lengthened over natural males with their normally swordless tails (i.e., females appear to possess a bias for a trait that does not exist in the species). B) In a species of Xiphophorus where males do have swords (S+ fish), females prefer males with longer swords over males with shorter swords (i.e., female choice is based on variation in the male trait). Assuming you have four species of fish, Chester's Platty (CP) and Lester's Platty (LP) that both have swordless males (S-), and Jimmy's Swordtail (JS) and Slimmy's Swordtail (SS) that both have males with sword-ed tails (S+). Place these species on the cladograms below in a manner that 1) supports the sensory drive hypothesis, 2) refutes the sensory drive hypothesis, and 3) provide a short sentence justifying why your placement of the species supports and refutes the hypotheses, respectively. (Figure it out before you scrawl all over the cladograms). (15 points; ·= 73)