Gene flow is :
| 1. | the emergence of new species from pre-existing species |
| 2. | the exchange of genes during fertilization |
| 3. | mating between close relatives |
| 4. | the movement of genes between species populations |
Genetic drift is :
| 1. | random changes in gene frequency in a population |
| 2. | generational fluctuations in gene frequencies that produce no effect |
| 3. | changes due to interbreeding with other species populations |
| 4. | the effect of mutations as they spread through neighbouring populations |
The type of natural selection that operates to eliminate intermediate phenotypes in a population is known as:
| 1. | Directional selection | 2. | Disruptive selection |
| 3. | Stabilizing selection | 4. | Reverse selection |