The movement of individuals can provide ecological benefits in the form of enhanced recolonization potential and buffering from low densities; however, too much movement can synchronize local populations leading to a reduced effiicacy of recolonization. Similarly, population geneticists have long recognized that the movement of individuals, while supporting genetic and phenotypic diversity locally, can lead to a migrational load that inhibits local adaption from occurring. Understanding the balance of these processes can yield new insight into how the movmeent of individuals across a metapopulation impacts its ability to persist. We present a modeling framework that is robust to individual-level variation while accurately recognizing the discrete nature of events such as dispersal, brith and death in populaitons with overlapping generations. We apply this framework to a number of extisting questions in metapopulation ecology.
Results/Conclusions
We find that the common unimodal relationship between dispersal and persistence time (at the regional scale) is fundamentally altered when local adaptation is occuring. We find that persitence times are maximized at high dispersal rates. Here the detrimental effects of migrational load at high dispersal rates are mitigated because individuals may not contirbute to the gene-pool in cases where their traits are a poor match for their environment. The peak at intermediate dispersal rates is erased via the reduced efficacy of ecologial rescue when traits are mismatched. Incorporating both ecological and evolutionary perspectives into models of metapopulation dynamics generates the potential for such novel outcomes at the regional scale.