NEET BIOLOGY

Detailed explanation-1: -Genetic variation is the raw material of evolution. Without genetic variation, a population cannot evolve in response to changing environmental variables and, as a result, may face an increased risk of extinction.

Detailed explanation-2: -Compared with new mutations, adaptation from standing genetic variation is likely to lead to faster evolution, the fixation of more alleles of small effect and the spread of more recessive alleles.

Detailed explanation-3: -Adaptation is a dynamic evolutionary process where populations improve their fitness by accumulating beneficial alleles at loci controlling adaptive phenotypes. The polymorphisms contributing to adaptation can either be present as standing genetic variation at the onset of selection or emerge through mutations.

Detailed explanation-4: -Adaptations develop when certain variations or differences in a population help some members survive better than others (Figure below). The variation may already exist within the population, but often the variation comes from a mutation, or a random change in an organism’s genes.