Question

compare and contrast speciation by geographic isolation with speciation by polyploidy; give an example each

Answer 1

Geographical isolation specifies allopatric speciation . While speciation by polyploidy is sympatric speciation .

Similarly between these two is , they both involve reproductive barrier.

Difference between them is , allopatric speciation is genetic divergence permitted by geographical isolation . It increases genetic divergence among geographical isolated populations by means of genetic drift and selection. Example involves divergence of drosophila populations in the Hawaiian archipelago.

Sympathetic speciation, does not require geographic isolation. Instead, it relies on the development of reproductive isolation mechanism to allow divergence of the two subpopulation. The best known example of sympathetic speciation is the divergence of Rhagoletis pomonella.