Exam 8: Evolution at Multiple Loci: Linkage and Sex

When genotypes at one locus of a chromosome are nonrandomly associated with the genotypes at another locus of the same chromosome,the two loci are ________.

Certain loci that are in linkage disequilibrium with alleles of interest can be used as markers,which can then be useful in reconstructing the history of those alleles in populations.One such marker/allele is described in your text,where the allele in question has an insertion mutation,rendering an enzyme (glucocerebrosidase,or GBA)nonfunctional.The decay curve for linkage disequilibrium between this marker (named D1S305)and the nonfunctional GBA allele is shown in the accompanying figure.The orange lines show the present level of linkage disequilibrium and the inferred number of generations elapsed since the most recent common ancestor.Assuming an average generation time of 25 years,what is the best estimate for how long ago the most recent common ancestor existed?

The mode of reproduction in which females produce genetically identical offspring from unfertilized eggs is known as ________.

When a locus is discovered to be in linkage disequilibrium with nearby markers,and this allele is also found to occur in high frequency,it is logical to assume that this allele has been favored by ________.[two words]

Which of the following reduces linkage disequilibrium by disrupting overrepresented haplotypes and by generating new ones?

Mathematical analysis of Muller's ratchet reveals that the most important parameter in the rate at which the ratchet works is ________.

Which of the following can produce linkage disequilibrium?

The observation that some organisms can (and do)produce both sexually and asexually within the same population produces some interesting questions,most notably the one Maynard Smith theorized about: Will one mode of reproduction replace the other over time? Explain Smith's assumptions,and compare the predictions made by Smith's model with what is actually observed in nature.Are either of these assumptions violated in real life? Why or why not?

Besides selection on multilocus genotypes,there are two other mechanisms that can create linkage disequilibrium.What are they?

In terms of population genetics,sexual reproduction on a functional level involves two necessary conditions.What are these conditions?