NEET BIOLOGY

Detailed explanation-1: -Natural selection, genetic drift, and gene flow are the mechanisms that cause changes in allele frequencies over time. When one or more of these forces are acting in a population, the population violates the Hardy-Weinberg assumptions, and evolution occurs.

Detailed explanation-2: -Genetic variations that alter gene activity or protein function can introduce different traits in an organism. If a trait is advantageous and helps the individual survive and reproduce, the genetic variation is more likely to be passed to the next generation (a process known as natural selection).

Detailed explanation-3: -Microevolution reflects changes in DNA sequences and allele frequencies within a species over time. These changes may be due to mutations, which can introduce new alleles into a population.

Detailed explanation-4: -Gene Flow (Migration) If new alleles are introduced into a population through migration and intermarriage, a change will occur in the relevant allele frequencies. This slow diffusion of alleles across racial or geographical boundaries is known as gene flow.