Hunting reduced the population size of the northern elephant seal 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. How is the lack of genetic variation related to the hunting episodes of the 1800's?
Responses
A Genetic drift occurred: the few individuals left behind were the seals that passed on that specific gene pool.Genetic drift occurred: the few individuals left behind were the seals that passed on that specific gene pool.
B Adaptation occurred: some seals were able to adapt to the hunting environment and they survived to pass on their genes.Adaptation occurred: some seals were able to adapt to the hunting environment and they survived to pass on their genes.
C During the 1800's some northern seals migrated and were able to survive. That gene pool is found in the current population.During the 1800's some northern seals migrated and were able to survive. That gene pool is found in the current population.
D Natural selection occurred: only the strongest northern elephant seals survived in the 1880's and that restricted gene pool exists today.
A. Genetic drift occurred: the few individuals left behind were the seals that passed on that specific gene pool.
The correct answer is D. Natural selection occurred: only the strongest northern elephant seals survived in the 1880's and that restricted gene pool exists today.
In the 1800s, hunting greatly reduced the population size of northern elephant seals, leaving only a few individuals remaining. These few individuals had to survive extreme hunting pressures, which means that only the strongest seals were able to survive and reproduce. This is an example of natural selection, where individuals with advantageous traits are more likely to survive and pass on their genes to the next generation.
As a result of this intense hunting pressure, there was a significant decrease in genetic variation within the population. Genetic variation refers to the diversity of genes within a population, and it is important for the long-term survival and adaptability of a species.
With only a small number of individuals surviving the hunting episodes, the gene pool of the northern elephant seal population became greatly limited. The surviving seals possessed a restricted set of genes, as only those individuals with the most beneficial traits were able to survive the hunting pressure.
Therefore, the lack of genetic variation in the current population of northern elephant seals is a consequence of the intense hunting episodes in the 1800s, where natural selection favored the survival of only the strongest individuals with the most advantageous traits.