<P> In biology, a population is all the organisms of the same group or species, which live in a particular geographical area, and have the capability of interbreeding . The area that is used to define a sexual population is defined as the area where inter-breeding is potentially possible between any pair within the area, and where the probability of interbreeding is greater than the probability of cross-breeding with individuals from other areas . </P> <P> In sociology, population refers to a collection of humans . Demography is a social science which entails the statistical study of human populations . Population in simpler terms is the number of people in a city or town, region, country or world; population is usually determined by a process called census (a process of collecting, analyzing, compiling and publishing data) </P> <P> This article refers mainly to human population . </P> <P> In population genetics a sexual population is a set of organisms in which any pair of members can breed together . This means that they can regularly exchange gametes to produce normally - fertile offspring, and such a breeding group is also known therefore as a Gamo deme . This also implies that all members belong to the same species . If the Gamo deme is very large (theoretically, approaching infinity), and all gene alleles are uniformly distributed by the gametes within it, the Gamo deme is said to be panmictic . Under this state, allele (gamete) frequencies can be converted to genotype (zygote) frequencies by expanding an appropriate quadratic equation, as shown by Sir Ronald Fisher in his establishment of quantitative genetics . </P>

A population is defined as all of the inhabitants of a given country or area considered together