Dynamical mechanism for coexistence of dispersing species without trade-offs in spatially extended ecological systems

Most prior studies on the role of dispersal in the coexistence of competing species have emphasized the need for trade-offs between competitive and colonizing abilities for coexistence. Theoretical studies of the evolution of dispersal recently have revealed an alternative mechanism for the coexistence of species differing solely in dispersal rates in spatially extended systems. We present an analysis and numerical evidence indicating that chaotic synchronism, occurring in an extremely intermittent form, is an important feature of the spatiotemporal variation in fitness required for the coexistence of species without trade-offs.