Describing groups of similar organisms that, although in close proximity and theoretically capable of interbreeding, do not interbreed because of differences in behaviour, flowering time, etc. Seeisolating mechanism. Compareallopatric.
Geography
Living in the same region; a term used in ecology to specify separate species whose territories overlap. Sympatric speciation is the emergence of two species from a single, mixed-parent population, without the aid of geography. Jiggins (2006) Current Biol. 16, 9 finds evidence of sympatric speciation in isolated island habitats.