Class 12 NEET Biology Evolution Questions Part 1

Allele frequency in a population can remain constant only if individuals of the population randomly interbreed. Generally it never happens in nature and species populations exist in small groups of randomly breeding subpopulations. Thus allele frequency between two subpopulations may differ but allele frequency within the subpopulation will remain constant. Such subpopulations are termed Mendelian populations or deme. Exchange of genes between demes takes place occasionally, Mutation, gene flow (due to migration), etc. may te change the allele frequency of the subpopulation.