One of the important consequences of geographical isolation is

91 2007 AIPMT-PRE EvolutionSpeciation Easy
One of the important consequences of geographical isolation is
A preventing speciation
B speciation through reproductive isolation
C random creation of new species
D no change in the isolated fauna

Detailed Solution

Geographical isolation is the separation of a population into two or more groups by a physical barrier such as a mountain, a river or the sea.
The barrier stops the flow of genes between the separated populations.
Each population then accumulates different mutations and is subjected to different selection pressures and genetic drift, so the populations diverge genetically.
In course of time they become so different that they can no longer interbreed even if they come together again; that is, they become reproductively isolated.
Reproductive isolation marks the formation of new species. This is called allopatric speciation.
So geographical isolation promotes speciation; it does not prevent it, and the isolated fauna does change in a non-random way through selection.
So the important consequence is speciation through reproductive isolation.

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