Why is genetic isolation considered a threat to wildlife populations?

Genetic isolation poses a significant threat to wildlife populations primarily because it leads to inbreeding and reduced genetic health, as well as decreased adaptability of the population. When individuals within a population are unable to interbreed with other populations due to barriers such as habitat fragmentation or geographical separation, the gene pool becomes restricted.

Inbreeding occurs when closely related individuals mate, which can result in an increased likelihood of offspring expressing harmful genetic traits. This reduces the overall fitness of the population, making them more susceptible to diseases and reducing their chances of survival.

Moreover, a limited genetic diversity hampers the population’s ability to adapt to changing environmental conditions. When faced with threats such as climate change, diseases, or habitat alterations, a genetically diverse population is more likely to possess individuals with traits that can survive these challenges. Conversely, a genetically isolated population lacks this variability and may struggle to cope with new stresses, ultimately risking extinction.

Thus, both the inbreeding issue and the reduced adaptability resulting from genetic isolation combine to make it a serious threat to wildlife populations. This comprehensive understanding emphasizes why the answer encompasses both aspects, leading to option D being the most accurate choice.