Answers to Concept Checks

• 1. First genetic variation arises. Then various evolutionary forces cause changes in the frequency of genetic variants.
• 2. c
• 3. Microsatellites are often highly variable among individuals. They can be amplified with the use of PCR, and so they can be detected with a small amount of starting DNA. Finally, the detection and analysis of microsatellites can be automated.
• 4. b
• 5. Genetic drift can bring about changes in the allelic frequencies of populations and lead to genetic differences among populations. Genetic differentiation is the cause of postzygotic and prezygotic reproductive isolation between populations that leads to speciation.
• 6. c
• 7. b