Honors Natural Selection Practice

Adaptation

An inherited trait that helps an organism survive and reproduce

genetic variation

Differences among individuals in the composition of their genes or other DNA segments

Fitness

Ability of an organism to survive and reproduce in its environment

Inheritable Traits

how heredity influences a person's abilities, character, and behavior

aquired traits

Traits that are acquired during lifetime are pass on to offspring

evolution

change in a population over time

overproduction

more offspring are produced than can survive

competition

the struggle between organisms to survive in a habitat with limited resources

natural selection

mechanism by which natural pressures change populations and evolution occurs

common ancestor

The shared ancestor of new, different species that arose from one population

ancestral trait

more-primitive characteristic that appeared in common ancestors

Theory of Evolution

supported by multiple lines of evidence on how life on earth has changed over time

differential survival and reproduction

Individuals possessing traits well suited for the struggle for local resources will contribute more offspring to the next generation.

Sources of variation

random mutations, genetic recombination, migration

Microevolution

Evolutionary change below the species level; change in the allele frequencies in a population over generations.

Macroevolution

large-scale evolutionary changes that take place over long periods of time

disruptive selection

favors individuals at both extremes of the phenotypic range

directional selection

occurs when natural selection favors one of the extreme variations of a trait

stabilizing selection

Natural selection that favors intermediate variants by acting against extreme phenotypes

environmental pressures

the factors (abiotic or biotic) in an ecosystem which put pressure on an organism's survival and increase competition (whether inter-species or intra-species)