Biology Vocab Unit #7

Adaptation

An inherited character that enhances an organism’s ability to survive and reproduce in a particular environment.

Allele frequency

The proportion of a specific allele in a population

Abrupt appearance

How species undergo rapid evolutionary change, without any transitional forms

Analogous structures

Similar traits in different species that have different evolutionary origins but serve the same function

Artificial selection

The selective breeding of domesticated plants and animals to promote the occurrence of desirable traits.

Behavioral isolation

A reproductive barrier that prevents different species from mating; when species are reproductively isolated from others due to differences in behavior

Convergent evolution

The evolution of similar features in different evolutionary lineages, which result from living in similar environments.

Divergent evolution

A process that causes closely related species to become more different over time

Evolution

Descent with modification; the idea that living species are descendents of ancestral species that were different from present-day ones; also, the genetic changes in a populat ion from generation to generation.

Evolutionary mechanisms

Processes that change allele frequencies in a population over time, resulting in evolution

Extinction

The irrevocable loss of a species.

Fitness

How well organisms survive and reproduce in their environment, and how this contributes to the next generation's gene pool

Fossil Record

The chronicle of evolution over millions of years of geologic time engraved in which fossils appear in rock strata.

Gene flow

The transfer of alleles from one population to another as a result of the movement of individuals or their gametes.

Genetic drift

A change in the gene pool of a population due to chance. Effects of this are most pronounced in small populations.

Geographic isolation

The separation of a population of organisms from other populations of the same species by physical barriers which prevents interbreeding.

Macroevolution

Evolutionary change above the species level, encompassing the origin of a new group of organisms through a series of speciation events and the impact of mass extinctions on their diversity of life and subsequent recovery.

Microevolution

A change in a population’s gene pool over generations

Temporal Isolation

A reproductive barrier that prevents different species from interbreeding because they reproduce at different times.

Stasis

A period of little to no evolutionary change in a species over a long period of time