Final answer:
The example of a population bottleneck involving prairie chickens highlights the reduction in genetic diversity due to a severe decline in their population from habitat loss and hunting. This bottleneck effect, a type of genetic drift, occurs when a large portion of a population is wiped out, leaving a random sample of survivors that changes the genetic makeup of the future population.
Step-by-step explanation:
Population Bottleneck
An example of a population bottleneck involving prairie chickens can be traced back to when habitat loss and hunting pressure significantly reduced their numbers. Prairie chickens, once abundant in the Great Plains of the United States, experienced a drastic decline in population size. This led to a bottleneck effect, where the genetic diversity of the population was greatly reduced due to the survival of only a small number of individuals. As a consequence, the reduced genetic diversity resulted in inbreeding and an increase in the frequency of harmful alleles, adversely affecting the prairie chicken's long-term survival and adaptability.
Bottlenecks can result from various causes such as natural disasters, overhunting, or habitat destruction. Natural disasters like earthquakes and hurricanes can indiscriminately kill off large portions of a population, leaving a random sample of survivors that shapes the genetic structure of the subsequent population. Overhunting, a human-induced factor, has led to similar situations like the near extinction of the bison in the 19th century due to market and sport hunting. Genetic drift, through the bottleneck effect, alters allele frequencies by chance and can significantly impact a population's gene pool, especially if the surviving individuals possess alleles that were rare in the original population. This change can affect the population's ability to adapt to future environmental changes and may increase their risk of extinction.