AP BIOLOGY

Detailed explanation-1: -In small populations, individuals that carry a particular allele may leave more descendants than other individuals, just by chance. Over time, a series of chance occurrences can cause an allele to become more or less common in a population.

Detailed explanation-2: -In small, reproductively isolated populations, special circumstances exist that can produce rapid changes in gene frequencies totally independent of mutation and natural selection. These changes are due solely to chance factors. The smaller the population, the more susceptible it is to such random changes.

Detailed explanation-3: -Small populations tend to lose genetic diversity more quickly than large populations due to stochastic sampling error (i.e., genetic drift). This is because some versions of a gene can be lost due to random chance, and this is more likely to occur when populations are small.

Detailed explanation-4: -Genetic drift is a mechanism of evolution in which allele frequencies of a population change over generations due to chance (sampling error).

Detailed explanation-5: -Over time, these advantageous traits become more common in the population. Through this process of natural selection, favorable traits are transmitted through generations. Natural selection can lead to speciation, where one species gives rise to a new and distinctly different species.