1. Species:

A group of similar organisms that can breed and produce fertile offspring.

2. Population:

Group of individuals of the same species that live in the same area.

3. Gene pool:

All the genes, including all the different alleles for each gene, that are present in a population at any one time.

4. Frequency:

How often something occurs in a particular event.

5. Genetic Equilibrium:

Situation in which allele frequencies in a population remain the same.

6. Mutation:

Change in the genetic material of a cell.

8. Founder effect:

Modification of allele frequencies after migrating somewhere as a small part of the original population.

9. Migration:

Behavior of certain organisms that make them move from one environment to another seasonally.

10. Random mating:

Involves males in the population to mate with any female in the population, regardless of their "fitness" or other factors. Opposite of non-random mating.

11. Natural selection:

A gradual process where only the ones that are best suited for their environment get picked to live longer and reproduce with utmost success.

12. Artificial selection:

A process (with goal) where humans breed animals/plants selectively to acquire desired traits from their offspring.

13. Speciation:

New species being formed through processes like: divergent evolution, convergent evolution, gradualism, punctuated equilibrium, etc.

14. a) Directional selection:

Form of natural selection in which individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve.

b) Stabilizing selection:

Form of natural selection in which individuals near the center of a distribution curve have higher fitness than individuals at either end of the curve.

c) Disruptive selection:

Natural selection in which individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle of the curve.

15. Geographic/reproductive isolation:

When two populations are no longer able to interbreed due to separation by geographic barriers (rivers, mountains).

16. Divergent/convergent evolution:

Patterns of macroevolution, divergent evolution is when species evolve over time into several different species; convergent evolution is when different species evolve similarly into other species.

17. Niche:

Full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions.

18. Homologous/analogous structures:

Homologous structures are structures that are similar in different species of common ancestry; analogous structures are body parts that share a common function, but not structure.

19. Environment (abiotic/biotic):

The external surroundings including all the biotic and abiotic factors that surround and affect the survival and development of an organism or population.

20. Ecological equivalents:

Species that occupy similar niches in different geographical locations.

21. Vestigial organs:

Organs that are inherited from ancestors but has lost much or all of its original function.