BIOL 1108 CH. 20.1 EVOLUTION

20.1 Genetic Variation

population genetics

the study of patterns of genetic variation in natural populations and the forces that drive these variations. the goal is to make inferences about the evolutionary process from patterns of genetic variation in nature.

genetic variation

differences in DNA sequences

species

group of individuals that can share alleles/ genetic material with one another through reproduction

gene pool

consists of all the alleles present in all of the individuals in the species.

populations

interbreeding groups of species living in the same geographical area

Sources of genetic variation

Mutation, recombination

mutation

creates new variations

recombination

shuffles new variations/alleles made by mutations

somatic mutations

occur in the bodys tissues in non reproductive cells

germ-line mutations

occur in the reproductive cells (are passed down to the next generations of cells unlike the somatic mutations)

neutral mutations

genetic changes that have no effect on the organism, that being its survival or reproduction.

deleterious mutations

genetic changes that are harmful to an organism.

advantageous mutations

improves their carriers chances of survival or reproduction

statistical variance

measures how far a set of numbers is spread out from their average, or mean value.

• Gives a measure of how data is distributed around the mean.

• When zero, all values are the same.