Allopatric speciation occurs due to what factor?

Allopatric speciation occurs due to what factor?

• A. Geographic separation
• B. Chromosomal changes
• C. Hybridization
• D. Sympatric factors

Answer: (A)

Allopatric speciation is driven by geographic separation. When a physical barrier or great distance splits a population, gene flow between the groups is blocked. Each group then accumulates its own mutations, experiences different selection pressures, and undergoes genetic drift independently. Over many generations, these changes can lead to reproductive barriers, so individuals from the two groups can no longer interbreed even if they meet again, resulting in two distinct species. Other mechanisms involve different routes to speciation. Chromosomal changes can create new species without geographic separation (for example, polyploidy in plants), and hybridization can produce new lineages through interbreeding between species. Sympatric factors describe speciation occurring within the same geographic area due to ecological or behavioral differences, not because populations are physically separated.

Allopatric speciation is driven by geographic separation. When a physical barrier or great distance splits a population, gene flow between the groups is blocked. Each group then accumulates its own mutations, experiences different selection pressures, and undergoes genetic drift independently. Over many generations, these changes can lead to reproductive barriers, so individuals from the two groups can no longer interbreed even if they meet again, resulting in two distinct species.

Other mechanisms involve different routes to speciation. Chromosomal changes can create new species without geographic separation (for example, polyploidy in plants), and hybridization can produce new lineages through interbreeding between species. Sympatric factors describe speciation occurring within the same geographic area due to ecological or behavioral differences, not because populations are physically separated.