AP BIOLOGY

Detailed explanation-1: -Three mechanisms can cause allele frequencies to change: natural selection, genetic drift (chance events that alter allele frequencies), and gene flow (the transfer of alleles between populations).

Detailed explanation-2: -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-3: -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-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.