Exam 9: Evolution at Multiple Loci

Broad-sense heritability is defined as the ________ genetic variation divided by the ________ variation.

Consider a population with two loci (A, B), each with two alleles (A, a; B, b). What are the allele frequencies in this population if the haplotype frequencies are AB  0.35, Ab  0.15, aB  0.35, ab  0.15?

Without using mathematical symbols, explain the difference between broad- and narrow-sense heritability, including why one is more relevant to evolutionary studies.

Which of the following processes causes a neutral allele to increase in frequency because it is linked to an allele under selection?

Which of the following occurs when there is so much Mendelian variation within a population that not all possible genotypes could be represented in any given generation?

Which of the following does NOT represent a way in which genotype and phenotype can interact?

What two major concepts in biology were unified in the middle of the twentieth century?

Using the concept of adaptive landscapes, explain why a population may never reach its most fit phenotype.

Hardy-Weinberg at two loci The figure demonstrates Hardy-Weinberg frequencies at two loci. Which term represents the expected offspring haplotype frequencies for a cross between parents with aB and aB gametes?

An individual mapped within an adaptive landscape as a point located in a fitness valley would be characterized as having

Explain why one cannot compare the estimated heritability of fin length from different populations of the same fish species located in different lakes.

Multiple drug-resistant Staphylococcus aureus (MRSA) is a bacterium that has developed resistance to a wide range of antibiotics. Its resistance to penicillin, methicillin, and oxacillin is a result of the serial use of these antibiotics, which created a selective environment that favored resistance to the drug being used at the time. This resistance provides the bacteria with the ability to thrive in an environment with standard antibiotics, thereby making it a dangerous human health hazard. Why might one expect MRSA to retain penicillin resistance even if this antibiotic is rarely used?

The rediscovery of Mendelian inheritance caused increased scrutiny of Charles Darwin's theory of natural selection because of an apparent conflict in the two concepts. This conflict was based on the observation that Darwin focused on continuous traits, whereas Mendelian genetics deals with

If recombination between locus A and locus B (r) is 0.15, and the initial value of linkage disequilibrium (D) is 0.20, what will the value of linkage disequilibrium be after one generation of recombination? Show your work.

What would a map of phenotype space look like?

Selection can generate novel phenotypes by

Genotypic adaptive landscapes may better represent true adaptive landscapes than phenotypic adaptive landscapes when

In Lake Malawi cichlid fish, one can observe two color variants, Black Barred (BB) and Orange Blotch (OB). Sex in these fish is not determined by a sex chromosome but by a gene on an autosome, which produces either males or females. Both of these phenotypes are controlled by one biallelic locus each. OB females have a selective advantage in terms of their survivability: the OB phenotype allows females to blend into their background. OB males have a selective disadvantage because their reproductive coloration is disrupted and they have little mating success. How would this process influence the association of alleles at the color locus and sex-determining locus?

The observation of an offspring phenotype outside of the range of parental phenotypes is most likely due to

Consider two microsatellite loci (A, B), each with two alleles determined by the number of repeats of the microsatellite motif (A  15 or 17; B  27 or 31). You genotype an individual in this population and determine that its haplotype is 15/27 and 15/27. Are these alleles in coupling and/or repulsion? Explain your answer.