All species have limited distributions at broad geographical scales. At loc
al scales, the distribution of many species is influenced by the interplay
of the three factors of habitat availability, local extinctions and coloniz
ation dynamics. We use the standard Les ins metapopulation model to illustr
ate how gradients in these three factors can generate species' range limits
. We suggest that the three routes to range limits have radically different
evolutionary implications. Because the Levins model makes simplifying assu
mptions about the spatial coupling of local populations, ave present numeri
cal studies of spatially explicit metapopulation models that complement the
analytical model. The three routes to range limits give rise to distinct s
patiotemporal patterns. Range limits in one species can also arise because
of environmental gradients impinging upon other species. We briefly discuss
a predator-prey example, which illustrates indirect routes to range limits
in a metacommunity context.