Drought led to changes in seed size and toughness, and when only large, hard seeds were available the finches with thicker and stronger beaks had a selective advantage
In other cases, finches fed off flowers where long, thin beaks allowed them to reach deep into the flowers.
6) what is the name of the type of evolution that causes related organisms to become less alike?
divergent evolution
7)what does the geographic isolation of two populations of a species tend to increase difference between their gene pool?
because, with no gene flow between the two populations, their gene pools evolve independently of one another. (Gene flow tends to keep gene pools from diverging too much).
8) what is the name of the type of evoulution that causes distantly related organisms to become more alike?
convergent evolution
9) what is the name of the hypothesis that states that evoultion occurs at a slow constant rate through geologic time?
gradualism (don't know the name of a hypothesis, though)
10) list an environmental factor that could trigger MASS EXTINCTION
impact of a large asteroid or comet
11) what does there tend to be rapid evolution among the species that survive a mass extinction?
because many niches that were filled before the mass extinction are left unoccupied after the mass extinction
12) give example of analogous structures
wings of birds and wings of insects
13) give an example of homologous structures?
skeleton of forelimbs in whales and humans