Evolution Lecture Outline

Bio. 140    Evolution Lecture Outline

I.  What is Evolution?

II.  What causes evolution?

Review the requirements for Hardy-Weinberg Equilibrium (483-487)

When those requirements aren't met, evolution occurs

A. Four Causes of Evolution.  Can you define them and make up an example of each?  Does your example explicitly describe a change in allele frequencies (percentages)?

1. Mutation

2. Gene Flow

3. Genetic Drift

Why is population size so important?

What two random events create small populations, and how would those events cause genetic drift?

1.  

2.  

4.  Natural Selection - the mechanism made famous by Darwin.

Review the observations and inferences Darwin made to derive this mechanism.

III.  More about Natural Selection

A.  How does it differ from Artificial Selection?

B.  What is fitness?  (How does fitness relate to Natural Selection?)

What are the 2 rules for maximizing fitness?

1.

2.

C.  What is Sexual Selection and how is it related to Natural Selection?

Can you define and give an example of each of the following terms?

Sexual Selection:

Sexual Dimorphism:

Intrasexual selection:

Intersexual selection:

D.  Three trends (patterns) of Natural Selection.  Can you define them and make up an example of each?  Does your example explicitly describe a change in allele frequencies (percentages)?

1. Stabilizing Selection: Acts against extreme phenotypes and favors the more common, intermediate traits

2. Directional Selection: Favors a relatively rare trait that deviates from the average for that population.

Know the Peppered Moth example

3. Disruptive (Diversifying) Selection: Acts against the more common, intermediate phenotype and favors rare, extreme traits at both ends.