"It seemed logical to me once , the idea of macro-evolution . Let us suppose we have a species called `` X `` . If over a period of time the population became split by distance , we could call them `` X-1 `` and `` X-2 `` . Again , over a period of time , changes may have happened in one group , through mutations , so that `` X-1 `` may have changed so much that if the two populations were ever re-united , they 'd be unable to inter-breed ... thus they 'd be two distinct species . Evolutionaries call this Sympatric Speciation ."
"Actually , mutations accumulate in both populations ."
"Evolutionaries call this Sympatric Speciation ."
"Actually , mutations accumulate in both populations ."