Question

which lists the correct sequence of events for evolution to occur through isolation?
founding population arrives, biogeographic isolation occurs, genetic changes occur, reproductive isolation results
genetic changes occur, founding population arrives, reproductive isolation results, biogeographic isolation occurs
biogeographic isolation occurs, founding population arrives, genetic changes occur, reproductive isolation results
founding population arrives, genetic changes occur, biogeographic isolation occurs, reproductive isolation results

Explanation:

To determine the correct sequence for evolution through isolation, we analyze the logical order: First, a founding population arrives in a new area. Then, biogeographic isolation (due to geographic barriers) occurs, separating the population. Next, genetic changes happen in the isolated population over time. Finally, these genetic changes lead to reproductive isolation (the populations can no longer interbreed). Let's check each option:

• Option 1: founding population arrives, biogeographic isolation occurs, genetic changes occur, reproductive isolation results. This follows the correct order: arrival → isolation → genetic change → reproductive isolation.
• Option 2: Genetic changes can't occur before the founding population arrives. Incorrect order.
• Option 3: Biogeographic isolation can't occur before the founding population arrives (they need to be in the area first). Incorrect.
• Option 4: Biogeographic isolation should occur before genetic changes (isolation drives genetic divergence). Incorrect order.

Answer:

A. founding population arrives, biogeographic isolation occurs, genetic changes occur, reproductive isolation results