Evolution

3. the most common way for one gene pool to become isolated from another.
6. a characteristic that helps an organism survive
7. the name of the ship that Charles Darwin traveled on
11. Charles Darwin’s theory of evolution states that evolution happens by what?
12. structures that are similar
17. refers to the variety of living things
18. reduce the fitness of a hybrid offspring
19. when organisms disappear from the earth
20. a well-supported testable explanation of phenomena that have occurred in the natural world

1. when a species splits into a number of new forms when a change in the environment makes new resources available or creates new environmental challenges.
2. organs that serve no useful function in an organism
4. father of evolution
5. the name of Darwin's book; the ___ of species
8. the structures evolved independently
9. the study of fossil remains or other clues to past life
10. when two species evolve together
13. the formation of new and distinct species in the course of evolution
14. required for new species to form
15. had different shaped beaks depending on the island they were from
16. Darwin collected the preserved remains of ancient organisms, called ____