A population of chimpanzees was separated when the forest that they lived in had a section cut down and a town was built. After a long period of time, the chimpanzees came back into contact but were incapable of breeding. Which best describes the process that occurred?

The town divided the chimpanzee population, preventing the two groups from breeding with each other for a long time. Over time, they became reproductively isolated: when they met again, they could no longer breed. The formation of reproductively isolated groups is speciation, so the answer is speciation.

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