Galápagos medium ground finches are found on santa cruz and san cristóbal islands, which are separated by about 100 km of ocean. occasionally, individuals from either island fly to the other island to stay. this can alter the allele frequencies of the population through which of the following mechanisms?
natural selection
genetic drift
gene flow
mutation

Gene flow

Explanation:

Gene flow, also known as migration, gene migration or allele flow, is the movement of genetic material when individuals move from one place to another, this migration generates a modification in the allele frequencies combining the gene pool between both populations. This is exactly what is happening in the example given.

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