Evolution and Natural Selection

4. Some species have evolved morphological adaptations that allow them to blend in with their environments, this is called ______.
5. The ___ can occur when a small sample of a population settles in a location separated from the rest of the population.
11. ________, also called divergent evolution, can occur in a relatively short time when one species gives rise to many opportunity.
14. ______ are structures that are the reduced forms of functional structures in other organisms.
15. Today, biologists use the term _____ to define cumulative changes in groups of organisms through time.
16. Those less equipped would die, this is the process of ______.
18. The process of directed breeding to produce offspring with desired traits,referred to as selective breeding was called _____ by Darwin.
19. An ___ is an early,pre-birth stage of an organism's development.
20. In ____, one species evolves to resemble another species.

1. _____ Can be used for the same purpose and can be superficially similar in construction but are not inherited from a common ancestor.
2. Any change in the allelic frequencies in a population that results from chance is called ______.
3. _______ is a process that splits a population into two groups.
6. _____ occurs when a population declines to a very low number and then rebounds.
7. Operates to eliminate extreme expressions of a trait when he average expression leads to higher fitness.
8. If an extreme version of a trait makes an organism more fit ________ might occur.
9. _____ are newly evolved features, such as feathers, that do not appear in the fossils common ancestors.
10. Darwin's study of the distribution of plants and animals around the world in a field of study now called _____.
12. Anatomically similar structures inherited from a common ancestor are called _______.
13. When allelic frequencies remain constant, a population is in genetic equilibrium.
17. ____ is a measure of the relative contribution that an individual trait makes to the next generation