1. Notes: What is Evolution (Genetic Basis)
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2. Population Genetics- the study of how species evolve from a genetic point of view.
A population is a group of the same species in the same given area.

3. While an individual may show variations from the rest of their population (species), they themselves cannot evolve.

4. A mutation (good, bad, neutral) may make an organism different, but cannot make a species evolve unless it is in the gene pool!
Only a POPULATION can evolve, an individual cannot!!

5. Speciation is the formation of a new species through modifications of an already existing species.
In other words, new species are simply changed versions of old species.

6. Speciation is usually the result of….
1. Geographic Isolation- the physical separation of members of a population. The two separate groups/populations then may become different from one another due to:
A lack of gene flow (mating) between the two groups in a population (which are now divided)
Natural Selection (different environments favor different traits)

7. Geographic Isolation

8. Reproductive Isolation
2. Reproductive Isolation- genetic changes that make groups of organisms within a population different from one another (without being separated geographically).
This can be a direct result of geographic isolation!

9. Natural Selection means that the environment (nature) usually favors one form of a trait over all others.
Another way of saying this is that a trait may be selected for.
Traits that are not favorable are said to be selected against.