Question

part a
there are four mechanisms that can cause changes in the frequencies of genes in populations: mutation, migration, genetic drift, and natural selection. all four are mechanisms of evolutionary change. what is genetic drift?
a in a population, is the changes in allelic frequencies of a gene that are due to chance.
b a random error/change in the dna sequence. these may be inherited or occur in cells during the lifetime of the organism.
c also known as gene flow. it is any movement of individuals and/or the genetic material they carry, from one population to another.
d there is variation in any population; differential reproduction occurs and over time a more advantageous trait exists in the population.

Explanation:

Genetic drift is defined as random changes in allelic frequencies due to chance events (e.g., small population size effects). Option A matches this definition. Option B describes mutation, Option C describes migration (gene flow), and Option D describes natural selection.

Answer:

A. In a population, it's the changes in allelic frequencies of a gene that are due to chance.