Question

The bottleneck effect is used to describe an event where a population decreases. One example involves the northern elephant seal. They have a reduced genetic variation due to a population bottleneck humans inflicted on them in the 1890s. Hunting reduced their population size to as few as 20 individuals at the end of the 19th century. Their population has since rebounded to over 30,000, but they have much less genetic variation than a population of southern elephant seals that was not so intensely hunted. Which phrase best explains this change if gene frequency? A) gene flow B) speciation C) genetic drift D) natural selection

Answer 1

The reduction in genetic variation within the northern elephant seal population due to intense hunting is best explained by genetic drift (Option C), particularly the bottleneck effect.

Step-by-step explanation:

The change in gene frequency within the northern elephant seal population after a dramatic population decrease due to hunting in the 1890s can be best explained by the concept of genetic drift, specifically a scenario known as the bottleneck effect. This occurs when a significant event, whether natural or human-caused, drastically reduces the size of a population, leaving a small, random sample of individuals to contribute their genes to future generations. The result is a population with substantially less genetic variation, as many alleles present in the original population may be lost. On the other hand, the founder effect relates to a new population being started by a small group of individuals, influencing genetic frequencies in a different context.

Answer 2

The correct option is C) genetic drift

Step-by-step explanation:

Genetic drift can be described as any changes which occur in the allele frequency of a gene. Genetic drift can be caused due to various factors like hunting by humans or natural disasters. As a result of genetic drift, there will be lesser genetic variation present among the population. Some types of allele might get completely removed from the population due to genetic drift. As a result, the offspring produced will not have those alleles in them causing reduced variations.