What is the process by which a population splits into two or more reproductively isolated groups?

What is the process by which a population splits into two or more reproductively isolated groups?

• A. Genetic drift
• B. Speciation
• C. Natural selection
• D. Mutation

Answer: (B)

Speciation is the process by which a population splits into two or more reproductively isolated groups. When gene flow between parts of a population is reduced or blocked—often by geographic barriers, or by differences in ecology or behavior—each group begins to evolve independently. Mutations arise, and natural selection and genetic drift shape the separate groups differently, gradually building barriers to interbreeding even if the populations come back into contact. Over time, these reproductive barriers solidify, and the groups become distinct species. Genetic drift, natural selection, and mutation can all contribute to divergence, but speciation is the overarching process that results in reproductively isolated lineages.

Speciation is the process by which a population splits into two or more reproductively isolated groups. When gene flow between parts of a population is reduced or blocked—often by geographic barriers, or by differences in ecology or behavior—each group begins to evolve independently. Mutations arise, and natural selection and genetic drift shape the separate groups differently, gradually building barriers to interbreeding even if the populations come back into contact. Over time, these reproductive barriers solidify, and the groups become distinct species.

Genetic drift, natural selection, and mutation can all contribute to divergence, but speciation is the overarching process that results in reproductively isolated lineages.