Sympatric means a situation where two or more different species live in the same geographic area or habitat without any physical barrier separating them.
«I think it's probably one of the best, and only, examples of sympatric speciation in birds,» says Robert Zink of the University of Minnesota, Twin Cities. (sciencemag.org)
This indicates that there are likely pre-mating barriers to heterospecific mating; previous research in my lab has indicated that the face patterns exhibited by guenons are likely contributing to maintaining species boundaries and have been under selective pressures to diversify (i.e. there is evidence of character displacement in sympatric species groups). (people.nyuprimatology.com)
Evolutionary biologists have long argued about whether it's possible for a new species to arise in a population that isn't separated by geographic barriers, such as an ocean or a mountain range — a process called sympatric speciation. (sciencemag.org)