Sympatric Speciation is the genetic divergence of multiple populations (from a single parent species) inhabiting the same geographic region; such that those populations become different species.
Etymologically, sympatry is derived from the roots sym- (meaning same, alike, similar, or fellow) and -patry (meaning homeland or fatherland).
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Speciation that occurs as a result of divergence of two populations occupying the same geographical area. It is due to reproductive isolation of subpopulations of a species without physical isolation. One well-established mechanism is polyploidy.