Biology Evolution Unit

microevolution

a change in allele frequencies

macroevolution

genetic changes lead to the development of a new species

evolution

change in a species over time

phenotypes

observable traits

evidence of evolution

population shrinks in size due to chance events, non-random mating, genetic mutation, migration, natural selection

genetic drift

small population

gene flow

migrations

natural selection

causes a trait to become more or less common in a population based on usefulness and if it aids the organisms in staying alive

natural selection is present if

variability, heritability, and a reproductive advantage are present (all three MUST be present)

Natural selection

causes a trait to become more or less common in a population based on usefulness and if it aids the organisms in staying alive.

Evidence of evolution

population changes size due to chance events, non- random mating, genetic mutation, migration, natural selection.

Microevolution

a change in allele frequencies.

Macroevolution

genetic changes lead to the development of a new species.