Evolution by Natural Selection

species

a group of similar organisms that can mate with each other and produce fertile offspring

fossil

the preserved remains or traces of an organism that lived in the past

adaptation

a trait that helps an organism survive and reproduce

evolution

the gradual change in a species over time

scientific theory

a well-tested concept that explains a wide range of observations

natural selection

the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species

variation

any difference between individuals of the same species

homologous structures

parts that are similar in related species; provide evidence of inheritance from common ancestor

branching tree

a diagram that shows how scientists think different groups of organisms are related

vestigial structures

parts of an organism that have no apparent use, inherited from an ancestor with a usable form of the part

embryology

the branch of biology that deals with early development of organisms

selective breeding

the process by which humans breed plants and animals to develop particular characteristics

trait

a characteristic that an organism can pass on to its offspring

inheritance

the passing of traits from parents to biological offspring

ancestor

a deceased organism from which other organisms are descended, usually by many generations

DNA

the genetic material, found in an organism's cells, that carries information about an organism and is passed from parent to offspring

extinct

a species that does not have any living members