LIFE SCIENCE

Detailed explanation-1: -Europeans migrating to North America and mating with Native Americans to create a new gene pool. Domesticated reindeer escape and mate with native caribou in Alaska and produce offspring with new traits.

Detailed explanation-2: -An important evolutionary force is gene flow: the flow of alleles in and out of a population due to the migration of individuals or gametes.

Detailed explanation-3: -The bottleneck effect is an extreme example of genetic drift that happens when the size of a population is severely reduced. Events like natural disasters (earthquakes, floods, fires) can decimate a population, killing most individuals and leaving behind a small, random assortment of survivors.

Detailed explanation-4: -Genetic Drift Example Consider a population of rabbits with brown fur and white fur, white fur being the dominant allele. Due to genetic drift, only the brown population might remain, with all the white ones eliminated. A couple with brown and blue eyes has children with brown or blue eyes.

Detailed explanation-5: -In humans, founder effects can arise from cultural isolation, and inevitably, endogamy. For example, the Amish populations in the United States exhibit founder effects because they have grown from a very few founders, have not recruited newcomers, and tend to marry within the community.