Ancestor
a related organism from a previous generation
Fossil
evidence of life from the past, such as fossilized bones, footprints, or leaf prints
Population
a group of the same type of organism living in the same area
Descendant Species
a more recent species that evolved from an ancestor population
Shared Structure
a body structure in two or more species that features the same parts (for example, the same bones)
Paleontologist
a scientist who studies fossils in order to understand the ancient history of life on Earth
Limb
an organism's arm, leg, or wing
Generation
a group of individuals born and living at about the same time
the process by which species adapt to environmental changes over a very long time
Related
sharing a common ancestor population
Body Structure
a part of an organism (for example, one or more bones)
Mutation
a random change to a gene that sometimes results in a new trait
Species
a group of organisms of the same kind (in one or more populations) that do not reproduce with organisms from any other group
Evolutionary Time
the very long time that spans the history of Earth, from the very first cellular life to the present
Extinct
having died out completely and no longer alive anywhere on Earth
Inherit
to receive genes from a parent
Natural Selection
the process by which the distribution of traits in a population changes over many generations
Speciation
the process by which one population evolves into two or more different species.
Common Ancestor Population
an older population from which two or more newer species descended
Stability
when something stays mostly the same over time