What happens to genetic diversity during migration?

Genetic diversity can indeed increase depending on the source of the migrants. When a population experiences migration, individuals from different populations may introduce new alleles and genetic variants into the resident population. This influx of new genetic material can enhance the overall genetic diversity, particularly if the migrant population has different genetic characteristics than the resident population.

For instance, if a small, isolated population receives migrants from a larger, genetically diverse population, the resulting hybridization can lead to an increase in allelic variation and overall genetic diversity. This process is vital for the adaptability and survival of populations, as greater genetic diversity often allows for a more extensive pool of traits that can confer advantages in changing environments or against diseases.

In contrast, homogenization due to migration would typically refer to a decrease in genetic diversity, usually when a dominant or widespread genetic makeup overtakes the local variations. Stating that genetic diversity remains unchanged is an oversimplification, as the effects of migration can vary greatly based on the relationship and genetic backgrounds of the populations involved. Lastly, saying that genetic diversity is entirely lost during migration neglects the potential for genetic introduction and fusion that can occur, which often adds to the genetic landscape.