Question

explain about the factors that affect variation as well as H. weinberg principle?

Answer 1

The Hardy Weinberg principle says that in a population the frequencies of alleles are fixed and remain the same over generations. As a result, the gene pool of a population remains constant and the population is said to be in genetic equilibrium. However, this equilibrium is affected by five factors:

1. Mutations that are sudden changes in genes. Mutation may be caused due to various physical or chemical factors.
2. Gene flow or gene migration. It occurs by the means of migration of individuals (in case of animals) or of propagules (in case of plants) into or out of a population. The individuals bring in or take out some genes from the population and thus disturb the equilibrium.
3. Genetic recombination which occurs by crossing over during sexual reproduction.
4. Natural selection that selects a particular phenotype and works towards increasing its frequency.
5. Genetic drift which is change in the gene frequencies in a population by a chance event.

In fact, this principle considers the population to be fixed and not evolving, which is a theoretical condition. All the factors mentioned above cause variations in a population and gradually lead towards evolution of a new species.