What is population?
An ecosystem consists of many species. Species is a group of living organism comprising of similar individuals capable of exchanging genes through interbreeding. The individuals of a same species of a particular region are called population.
Population definition: “A group of individuals of a particular species occupying a definite space, in which the individuals interact, interbreed and exchange genetic materials.”
What is Population Genetics?
Apart from its ecological significance, population has a important role in the process of evolution. We generally have a wrong notion that an individual in a population is evolving during the course of evolution of a species. But in reality, not the individuals but the population only can evolve. Thus population forms the basic unit of evolution, not the species. We also know that for the process of evolution to occur in a system, there should be changes in the genetic constitution. Since the population is undergoing evolution and not the individuals, the changes should be in the genetic constitution of the population. There is considerable difference between the inheritance of genes in the population and that in the individuals. Population genetics is the study of distributions and changes of allele frequency and interaction of alleles in a population. Study of population genetics is very essential for understanding the species adaptation and evolution.
As we mentioned earlier, the process of evolution to occur in a population, the population should face evolutionary forces. A population is usually prone to four main types of evolutionary forces such as:
(1). Natural selection
(2). Genetic drift
(4). Gene flow (migration)