Population

When an area is inhabited by a group of individuals of the same species, it is known as a population. Some populations are isolated, rarely reproducing, while others are denser. For example, a mountain range or unconnected river can separate a population. Individuals near a population center are more closely related to members of the same population than other populations because they are more likely to breed with those of the same population. In a population's gene pool, all of the alleles in the individuals of the population are considered at all gene loci. An allele is said to be fixed in a gene pool if all members are homozyous for the same allele, meaning they all have a specific trait. However, there are usually two or more alleles for a gene. To refer to a population's frequencies of alleles and genotypes, the term genetic structure is used.

An example of a population of ducks is depicted above.

Works Cited:
Campbell, Neil, Jane Reece, and Lawrence Mitchell. “The Evolution of Populations.” Biology. Fifth ed. Menlo Park: Jim Green Publishing, 1999. 429. Print.