Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

What role does immigration play in the evolution of populations?

1. It decreases genetic diversity

2. It enhances genetic variation

3. It has no impact on evolution

4. It leads to speciation events

The correct answer is: It enhances genetic variation

Immigration plays a significant role in enhancing genetic variation within populations. When individuals from different populations migrate and interbreed, they introduce new alleles into the gene pool. This influx of genetic material increases the overall genetic diversity, which is crucial for a population's ability to adapt to changing environments and survive various challenges, such as disease and climate change. The increased genetic variation can also provide a broader range of traits upon which natural selection can act, ultimately influencing the evolution of the population. In contrast, the other options either misrepresent or minimize the impact of immigration on genetic diversity and evolutionary processes. Although one might argue that immigration could lead to speciation under certain conditions, this is not its primary role in the context of genetic variation. Therefore, the enhancement of genetic variation through immigration is a foundational principle in evolutionary biology.