AP BIOLOGY

Detailed explanation-1: -Natural selection, genetic drift, and gene flow are the mechanisms that cause changes in allele frequencies over time.

Detailed explanation-2: -There are five key mechanisms that cause a population, a group of interacting organisms of a single species, to exhibit a change in allele frequency from one generation to the next. These are evolution by: mutation, genetic drift, gene flow, non-random mating, and natural selection.

Detailed explanation-3: -Answer and Explanation: New alleles appear in a species by mutation. Explanation: Mutation can be defined as a change or alteration in the sequence of DNA that results in a change in the expressed phenotypic traits of the DNA sequence or gene. The mutation is responsible for introducing new alleles in the gene pool.

Detailed explanation-4: -Allele frequencies in a population may change due to gene flow, genetic drift, natural selection and mutation. These are referred to as the four fundamental forces of evolution.

Detailed explanation-5: -Although natural selection is the mechanism of evolution most commonly discussed, other evolutionary mechanisms also change the frequencies of traits (and the genes that control them) in populations. These include mutation, genetic drift and migration.