Most often the factor that initiates the speciation of two populations is :

1. geographic separation

2. inability of gametes to fuse

3. different courtship behaviors

4. different copulatory organs

Genetic drift occurs when a few individuals of a species colonize an island. This phenomenon is :

1. the bottleneck effect
2. the founder effect
3. assortative mating
4. random mating 

After pollution destroyed lichens on the trees, the survival of the dark-colored peppered moths increased, because they were: 
1. protected from carcinogens 
2. protected from lichen poisons 
3. more robust 
4. protected from predation

Darwin believed that a giraffe has a long neck because:

Which of the following pairs of organs do not represent analogous organs? 

In a sympatric speciation, there is:

Which of the following types of natural selection reduces variation but does not change the mean value?

(1) Directional

(2) Stabilizing

(3) Disruptive

(4) All of these

In genetic drift, the term "genetic bottleneck" means:

1. reduction in allele frequencies or richness

2. random change in allele frequency by chance alone

3. sudden increase in the number of individuals

4. reproductive isolation of the population

Which of the following is not a precondition for Hardy-Weinberg Equilibrium?

1. The population should be large

2. The mating should be assortative

3. There is no gene flow into or out of the population

4. All offspring should be equally fertile.