Evolution Unit vocabulary

Evolution

The gradual change in a species over time

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Variation

Any difference between individuals of the same species.

Fitness

Ability of an organism to survive and reproduce in its environment

Adaptation

A trait that helps an organism survive and reproduce

Selective pressures

factors in the environment that influence reproductive success in individuals

struggle for existence

members of each species compete regularly to obtain food, living space, and other necessities of life

survival of the fittest

Process by which individuals that are better suited to their environment survive and reproduce most successfully; also called natural selection

artificial selection

selective breeding of plants and animals to promote the occurrence of desirable traits in offspring

allele frequency

a measure of how common a certain allele is in the population

gene pool

All the genes, including all the different alleles for each gene, that are present in a population at any one time

Speciation

Formation of new species in the course of evolution

Biodiversity

the variety of life in the world or in a particular habitat or ecosystem.

Fossil

A trace of an ancient organism that has been preserved in rock.

Embryology

study of embryos and their development

coevolution

Process by which two species evolve in response to changes in each other

common ancestor

An ancestral species from which multiple species have evolved, sharing certain traits.

homologous structures

Anatomical features in different species that have similar structures and origins but may serve different functions, indicating a common ancestry.

vestigial structures

Remnants of organs or structures that had a function in an early ancestor but are reduced or nonfunctional in later descendants, providing evidence of evolutionary change.

fossil record

The preserved remains or traces of organisms from the past, providing evidence for the history of life on Earth and the process of evolution.

molecular biology

Evidence for evolution can be found in the study of DNA and genetic similarities among different organisms, revealing evolutionary relationships.