A scientific theory explaining how living things descended from earlier organisms.
What is evolution?
100
The preserved remains or traces of an organism that lived in the past.
What are fossils?
100
When all members of a species disappear from Earth.
What is extinction?
200
Segments of DNA that determine characteristics in an organism.
What are genes?
200
Any difference between individuals of the same species.
What is variation?
200
Species in danger of becoming extinct in the near future.
What are endangered species?
300
The genetic material inside a cell that carries information about an organism.
What is DNA?
300
Specific characteristics that organisms can pass to their offspring.
What are traits?
300
Species that could become endangered in the near future.
What are threatened species?
400
The millions of fossils that scientists have collected and provide clues about how and when a new species evolved and how organisms are related.
What is the fossil record?
400
A trait that increases an organism's ability to survive and reproduce.
What is an adaptation?
400
A role of an organism in its habitat, or how it makes its living.
What is a niche?
500
Similar structures that related species have inherited from a common ancestor.
What are homologous structures?
500
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.