Four Speciations Explained: Parapatric and Sympatric
Parapatric occurs when a smaller subpopulation remains within the habitat of its majority, but enters a different niche. Major physical changes won’t be as common nor will there be breeding between the two species groups. Yet there will be enough to make them different but not massively due to the shared habitat and possibility of commingling.
Sympatric occurs in an odd way. It’s incredibly rare and sometimes even controversial. It happens when there is no form of isolation between two different groups. This means they could be in the same habitat, comingle, and even mate between the two species types. In spite of this, the separation genetically will happen.