Final Answer:
After an initial founder or bottleneck event, one round of random mating will increase genetic diversity but may not fully restore the original diversity.
Step-by-step explanation:
When a population experiences a founder or bottleneck event, it undergoes a reduction in genetic diversity due to the limited number of individuals contributing to the next generation. In such scenarios, genetic drift becomes a significant factor, leading to the loss of alleles and reduced variation in the gene pool. To counteract this reduction in diversity, one round of random mating among the remaining individuals can introduce some new combinations of alleles, thereby increasing diversity compared to the immediate post-bottleneck state.
However, it's important to note that one round of random mating might not completely restore the initial genetic diversity present before the bottleneck event. The population's gene pool will likely still exhibit a lower level of diversity compared to its original state. This occurs because genetic drift has already eliminated certain alleles, and the subsequent random mating can only generate new combinations from the alleles that remain, unable to reintroduce the lost genetic variants.
Mathematically, consider a population that faced a bottleneck event resulting in a reduced number of individuals. Let's say the original population had alleles A, B, C, D, and E. After the bottleneck, only alleles A and B are present. One round of random mating might create combinations like AB, AA, or BB. While this generates new genotype combinations, it doesn’t restore alleles C, D, and E that were lost during the bottleneck event. Hence, although random mating after a bottleneck can increase diversity to some extent, it cannot fully recover the initial genetic diversity.