Question

There are two different, isolated populations of pronghorn antelope. Over 95% of herd A was killed during a disease outbreak, but its population quickly bounced back. Herd B was never exposed to the disease. The two herds currently have equal numbers. A completely different disease is likely to affect both populations this year. Which population would you be more concerned about surviving the disease?

Answer 1

Answer: Herd A is more prone to extinction than herd B.

Explanation:

Herd A has experienced a population bottleneck due to the outbreak of a disease and lost 95% of its original population. So, the remaining population would show less genetic diversity (due to loss of different alleles). This 5% population would inbreed to replenish the population to 100%. So, there are more chances of homozygous individuals and less genetic diversity in herd A. So, it is more susceptible to a new disease.

On the other hand, herd B contains genetic polymorphism. So, at least few individuals might contain beneficial alleles that provide resistance to the new disease.