Bio 280 Exam 1 Questions and Answers graded A

Neutral theory proposes that a. most molecular evolution is due to genetic drift rather than natural selection b. natural selection is not a major cause of phenotypic evolution c. most mutations are neutral with respect to selection d. the substitution rate is not related to the neutral mutation rate - A Natural selection acts on ________; _________ evolve. a. individuals, individuals b. individuals, populations c. populations, individuals d. populations, populations - B Which of the following can be concluded from the Grant's long-term study of the medium ground finch on Daphne Major? a. Beak size remained unchanged except during drought years. b. Beak size generally became larger over time. c. The direction of selection varied over time. d. The strength of selection was constant - C An animal's fitness is best measured by measuring its a. health and resistance to disease b. lifetime number of offspring c. body size d. strength and speed of movement - B As predicted by theory, in Buri's experiment with genetic drift in 107 populations of fruit flies, the bw75 allele was a. much more likely to become fixed than to be lost b. almost never lost or fixed c. much more likely to be lost than to become fixed d. about equally likely to be lost or become fixed - D The geographic distribution of the four Galapagos mockingbird species suggests that a. the Galapagos islands were once connected to the mainland b. their beak sizes diverged in response to different habitats on different islands c. all four are descended from single colonizer species d. the differences between the species stem from non-adaptive evolution - C For a single locus with two alleles (A1 and A2) in a population of a diploid species, if ½ of the individuals are heterozygous at the locus and ½ are homozygous A2, the frequency of allele A2 in the gene pool is a. 0.25 b. 0.75 c. 0.5 d. 0 - B