natural selection

Developmental Similarities

Similarities in the embryonic development stages of different organisms.

DNA

A reliable source for determining the relatedness of organisms based on genetic information.

Geographic Distribution

The observation of similar animals living in different locations as a result of different evolutionary paths.

Charles Darwin

An English naturalist known for his contributions to the theory of evolution by natural selection, particularly through his observations of finches in the Galapagos Islands.

Origin of Species

Darwin's 1859 publication outlining how living things change over time through natural selection.

Adaptation

Structures, functions, or behaviors that enable a species to survive; expressions of the organisms' genetic information.

Biodiversity

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

Evolution

The process by which the populations accumulate inherited changes over time.

Extinct

Describes a species of organism that has died out completely.

Fossil

The remains or impressions of prehistoric organisms in petrified form.

Fossil Record

What scientists examine in order to make inferences about the lives of prehistoric organisms.

Homologous Structures

Structures of the body that are similar to structures of other species' comparative parts; anatomical similarities.

Imprint

Trace fossils left behind by plants or animals lacking bones or shells.

Mutation

A change in an organism's DNA, either in the order of nitrogen bases or the entire chromosome.

Natural Selection

The process by which organisms with favorable traits survive and reproduce at a higher rate than organisms without that favorable trait.

Paleontologist

A scientist who studies fossils.

Radiometric Dating

Used to determine the actual age of fossils using radioactive elements.

Relative Dating

Used to determine the approximate age of fossils based on the location in layers of sediment.

Variation

Inherited trait that makes an individual different from other members of the same species and results from a mutation in the organism's genes.

Survival of the Fittest

Organisms most able or "fit" to survive in an environment will.