Use the following hypothetical situation to answer Questions 10 and 11 Imagine that there are two different populations of a single species of fish in a lake. One population of fish is pale-colored and one population is speckled.

Now imagine that some of the pale-colored fish migrated into the speckled population and introduced new alleles into the population. Will the population of dark-colored fish evolve?

Imagine that, over time, part of the lake dries up and there are now two separate bodies of water. The speckled and pale-colored fish are evenly mixed in the two smaller lakes. Will either population become more dominant?

The first scenario depends on the usage of the term "evolution". In the common idea of change from one species to another, no it is not as both populations of fish belong to the same species. If it's in vein of change in general, even within a species, then yes as there has been a genetic change within that population of fish and thus evolution. As for the second scenario it depends on lake conditions. If the smaller lakes are simply miniatures of the old lake then we can postulate that, provided genetic dominance doesn't favor one allele over the other, conditions are equally favorable for both populations and thus both will flourish in the new environment. However, if conditions favor one allele over the other, the more favorable trait will grow to be the dominate, if not only, expression of that species in the new lake.