Question

darwins finches came from a mainland species where some individuals were able to move to the islands and then spread from one island to another. is the genetic diversity of the new population of finches on the galápagos increased or decreased in relation to the population on the mainland, and what is this an example of? it decreased their genetic diversity because it represents an example of natural selection. it increased their genetic diversity because it represents an example of gene flow. it increased their genetic diversity because it would introduce new mutations into the population. it had no effect on their genetic diversity because the colonists have the same diversity as the mainland population. it decreased their genetic diversity because it represents an example of genetic drift.

Explanation:

• Genetic drift: It is a mechanism of evolution where allele frequencies of a population change over generations due to random chance. The founder effect is a type of genetic drift. When a small number of individuals (like the finches moving from the mainland to the Galápagos) establish a new population, the genetic diversity of the new population is likely to be lower than the original (mainland) population because only a subset of the original gene pool is represented.
• Natural selection: It acts on existing genetic variation to favor traits that are beneficial for survival and reproduction. But in this case, the initial change in genetic diversity is due to the small - sample (founder) effect, not natural selection acting on traits for survival immediately after colonization.
• Gene flow: It is the transfer of genetic material from one population to another. Here, the movement is from the mainland to the islands, but the key is that a small number of individuals (not a large - scale, continuous transfer that would increase diversity) colonized the islands.
• New mutations: There is no indication in the problem that new mutations occurred during the colonization process.
• Same diversity as mainland: Since only a subset of the mainland population (a small number of finches) colonized the islands, the genetic diversity cannot be the same.

Answer:

It decreased their genetic diversity because it represents an example of genetic drift.