AP BIOLOGY

Detailed explanation-1: -The mechanisms of evolution-like natural selection and genetic drift-work with the random variation generated by mutation. Factors in the environment are thought to influence the rate of mutation but are not generally thought to influence the direction of mutation.

Detailed explanation-2: -However, the idea that mutations are random can be regarded as untrue if one considers the fact that not all types of mutations occur with equal probability. Rather, some occur more frequently than others because they are favored by low-level biochemical reactions.

Detailed explanation-3: -Although mutations are thought to occur randomly in the genome, the distribution of mutations that cause biological diversity appears to be highly nonrandom.

Detailed explanation-4: -“We always thought of mutation as basically random across the genome, ” said Grey Monroe, PhD, an assistant professor in the University of California, Davis, department of plant sciences. “It turns out that mutation is very nonrandom and it’s nonrandom in a way that benefits the plant.

Detailed explanation-5: -This is because of selection. When mutations happen in parts of the genome that code for important genes, then very often those cells don’t survive. The harmful mutations are weeded out by selection, so we don’t see them.