Why is it likely that most speciation is allopatric? because disruptive selection between forms of traits in sympatric populations is always very strong. because vicariance events are common. because related species are always found in allopatry rather than in sympatry. because gene flow between populations prevents genetic divergence in sympatry. because gene flow between diverging populations is strong in allopatry.

Because gene flow between populations prevents genetic divergence in sympatry

Explanation:

Allopatric speciation is a form of speciation (creation of new species) that occurs as a result of geographic isolation. This means that a part of population becomes physically separated from the initial main population. There is no gene flow between these two populations and as a result the two populations  reach a high level  of genetic divergence. They can no longer interbreed which means they become two different species (speciation).

New populations evolve as result of mutation, genetic drift and natural selection.

Sympatric speciation is a form of speciation without geographic isolation, usually due to  the reproductive isolation or changes in the chromosomes of the organism.

d.

explanation: