The bottleneck effect is the sharp in the population size due to the fact of the environmental changes such as the famines and the floods and the diseases and other events that lead to the variation in the gene pool s and thus a reduction of the species with a smaller remaining genetic diversity. The genetic drift causes the bottlenecks and this can create a random alternation of the alleles and leads to the loss of the species.
Answer: A primary positive effect of the Columbian Exchange is increased food supply of both the Old World and the New World. Various crops such as wheat, barley, and rye, were introduced by Columbus and his followers.
