Practice Questions

TLS Online TPP Program

#Question id: 13129

Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation and on egg-to-adult survival. From a large source population, they randomly assigned eggs to three experimental populations of size N, equal to 20, 60, and0100. For later generations, they collected N eggs from each population and moved them into identical vials that co0ntained f2re0sh me4d0ium. Th6e0y coun8te0d the number of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by scoring alleles at several polymorphic loci and expressed as the average number of alleles at those loci. The results are summarized in Figure 1 and Figure 2 below.
Based on Figure 1, which of the following best describes the change in genetic variation over time?

#Unit 10. Ecological Principles

It increased in all three populations.
It was unchanged in the largest population and increased in the two smaller populations.
It was unchanged in all three populations.
It was unchanged in the two larger populations and declined in the smallest population.