Species
A group of similar organisms that can mate with each other and produce offspring that can also mate and reproduce.
Fossils
The preserved remains or traces of an organisms that lived in the past.
Evolution
The gradual change in a species over time.
Scientific Theory
is a well-tested concept that explains a wide range of observations.
Natural Selection
is the process by which individuals that are better adapted to their environment are more likely to survive and reproduce more than other members of the same species.
Variations
Any difference between members of the same species.
Homologous Structures
Similar structures that related species have inherited from a common ancestor.
Biodiversity
The number of different species in area.
Endangered species
Species that is in danger of becoming extinct in the near future.
Threatened species
Species that could become endangered in the near future.
Extinction
The disappearance of all the members of a species
Adaptation
A trait that helps an organism survive and reproduce