Final answer:
Small populations are vulnerable to a downward spiral leading to extinction due to ecological factors, genetic drift, and catastrophic events. They lack the genetic variation needed to adapt to changing conditions, and the only solution is to increase population size and genetic diversity.
Step-by-step explanation:
The question refers to the dynamics of small populations and their vulnerability to various ecological and genetic factors that can lead to a downward spiral in their numbers. This spiral can ultimately lead to extinction if not addressed. The negative feedback loop described, wherein increases in prey numbers lead to increases in predator numbers, which then leads to a decrease in prey numbers and thus predators, is an example of ecological interactions influencing population sizes. However, the core of the question revolves around why small populations are particularly at risk.
Small populations are more vulnerable to genetic drift because there is less genetic variation compared to larger populations. This is because the presence of a larger number of alleles in a large population's gene pool helps to buffer against changes in allele frequency due to random events. Catastrophic events, environmental fluctuations, and inbreeding depression can further exacerbate the vulnerability of small populations, potentially leading to extinction. The only solution to this downward spiral is increasing the population size and genetic diversity to mitigate these risks.