Background: Declines in population size can result in a loss of genetic diversity, and owing to genetic variation's role in the evolutionary potential of a species, this could in turn result in an observable Allee effect. As a species' population becomes smaller, its gene pool will be reduced in size as well. One possible outcome from this genetic bottleneck is a reduction in fitness of the species through the process of genetic drift, as well as inbreeding depression. This overall fitness decrease of a species is caused by an accumulation of deleterious mutations throughout the population. Genetic variation within a species could range from beneficial to detrimental. Nevertheless, in a smaller sized gene pool, there is a higher chance of a stochastic event in which deleterious alleles become fixed (genetic drift). While evolutionary theory states that expressed deleterious alleles should be purged through natural selection, purging would be most efficient only at eliminating alleles that are highly detrimental or harmful. Mildly deleterious alleles such as those that act later in life would be less likely to be removed by natural selection, and conversely, newly acquired beneficial mutations are more likely to be lost by random chance in smaller genetic pools than larger ones.Although the long-term population persistence of several species with low genetic variation has recently prompted debate on the generality of inbreeding depression, there are various empirical evidences for genetic Allee effects. One such case was observed in the endangered Florida panther (Puma concolor coryi). The Florida panther experienced a genetic bottleneck in the early 1990s where the population was reduced to ≈25 adult individuals. This reduction in genetic diversity was correlated with defects that include lower sperm quality, abnormal testosterone levels, cowlicks, and kinked tails. In response, a genetic rescue plan was put in motion and several female pumas from Texas were introduced into the Florida population. This action quickly led to the reduction in the prevalence of the defects previously associated with inbreeding depression. Although the timescale for this inbreeding depression is larger than of those more immediate Allee effects, it has significant implications on the long-term persistence of a species.

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: Whose town will have more genetic diversity?
Answer: Brian's town

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: Whose town will have less genetic diversity?
Answer: Molly's town

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: An Allee effect is currently happening in which town?
Answer: Molly's town

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: An Allee effect is not currently happening in which town?
Answer: Brian's town

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: Does Brian's town have a larger or smaller potential gene pool than Molly's?
Answer: larger

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: Does Molly's town have a larger or smaller potential gene pool than Brian's?
Answer: smaller

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: Which town's citizens will be on average better at running a race?
Answer: Brian's

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: Which town's citizens will be on average worse at running a race?
Answer: Molly's

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: Is the chance of inbreeding higher or lower in Molly's town?
Answer: higher

Situation: Molly and Brian are two friends who moved away from one another after becoming close in college. They still talk on the phone regularly and see each other a couple times a year. During a recent conversation, the subject of population comes up. Molly's town is currently increasing a steady decrease in population, and Brian's town has been seeing an increase in population.

Question: Is the chance of inbreeding higher or lower in Brian's town?
Answer: lower