How are two different species most likely to evolve from one ancestral species?
A) phylogenetically, due to heterozygote advantage in hybrids
B) allopatrically, after the ancestral species has split into two populations
C) sympatrically, by a point mutation affecting morphology or behavior

Question

Quizplus · Accepted Answer

Allopatric speciation occurs when a population is divided into two or more geographically isolated subpopulations. Over time, each subpopulation will evolve separately due to different environmental pressures and genetic drift. Eventually, the two subpopulations will become genetically distinct enough that they cannot interbreed, leading to two different species. This is the most common way that new species arise. Option A is incorrect as heterozygote advantage in hybrids would result in increased fitness of hybrid offspring, preventing speciation rather than promoting it. Option C is less likely as a single point mutation affecting morphology or behavior typically isn't enough to cause speciation, as it would require the accumulation of many mutations over time.

How Are Two Different Species Most Likely to Evolve from One