Final answer:
A population with little genetic diversity is more vulnerable to recessive lethal alleles and environmental changes due to the effects of genetic drift, such as the bottleneck effect and founder effect. These effects are more pronounced in small populations due to their limited gene pool and reduced genetic variability.
Step-by-step explanation:
If there is little genetic diversity in a population, the entire population may be more vulnerable to various forces such as recessive lethal alleles or to changing environmental conditions. Small initial population size and a decline in genetic diversity can lead to increased vulnerability. Genetic drift can be magnified by natural or human-caused events, such as natural disasters. These events can cause a bottleneck effect, leading to a large portion of the gene pool being wiped out and the survivors' genetic structure defining the population.Chance events like a storm killing all white rabbits in a population will diminish or even erase the allele for white fur. Similarly, the founder effect can occur when a new population is established by a small number of individuals, who may not represent the full genetic diversity of the original population, which can lead to increased occurrence of specific genetic disorders like Huntington's disease (HD) and Fanconi anemia (FA).Explaining why small populations are more vulnerable to genetic drift than large ones, it's because they have fewer individuals and thus a smaller gene pool, which is less stable and more susceptible to loss of genetic variability due to random events.