SELF-REINFORCING SPATIAL PATTERNS ENSLAVE EVOLUTION IN A HOST-PARASITOID SYSTEM

Spatially structured models of host-parasitoid interactions exhibit se lf-structuring into spatial patterns such as spiral waves and turbulen ce. We discuss the consequences of these patterns in an eco-evolutiona ry model of host-parasitoid interactions with evolution of the parasit oids' ability to disperse towards dense populations of hosts (termed t he aggregation strength). It turns out that the direction of, and the time-scale over which the evolutionary selection pressure acts depends on the type of spatial pattern a parasitoid finds itself in. Evolutio n tends to reinforce the existence of the prevalent local pattern. Mor eover, there is also competition between the patterns that ultimately determines the eco-evolutionary attractor. It is the interaction betwe en multiple processes across spatial and temporal scales that leads to the rich meso-scale behaviour. Predicting the evolutionary outcome fr om statistical measures and subprocesses is shown to give incorrect an d conflicting answers. Comparison with the behaviours of the complex G inzburg-Landau equation shows striking similarities on which we commen t. (C) 1997 Academic Press Limited.