Population – small subspecies of any given living organisms in which there take place primary evolutionary processes. It consists of several individuals who when crossing are capable to mutate, creating new species.
Population represents the whole group of representatives of a species which lives in any given territory in certain time. Its main sign – existence of similarity in a set of genes of her individuals which can strikingly differ from the next populations of the same look. This smallest community which is capable to develop independently for this reason population is called primary unit of evolution. One individual of any given look has no ability to evolve as its set of genes does not change during the life period. Population is a component of larger system of biological units – types. But some biologists consider that a look as the closed group it is quite viable throughout the long period, and quite possible it is represented to consider it an elementary component of evolution. It would be possible to agree with it in case the look is not divided into components. Differences in genetic parameters allows to create in population important criteria for its development. For this reason studying laws of evolving needs to be begun with accurate differentiation of structure in a look and its essence. As the look has the general genetic signs which influence all populations, in it emergence of mutations as favorable, and on the contrary is possible. Positive changes pretty fast extend across all territory occupied by a look and are built in structure of DNA of individuals, leading to evolving. Similar mutations are incapable to pass into other species as each of them possesses certain barriers (a difference in DNA, a difference in the reproduction periods, etc.). Negative mutations are capable to lead a look to destruction.