Evolutionarily Stable Dispersal Rates Do Not Always Increase with Local Extinction Rates

Abstract

Earlier models on the evolution of dispersal have suggested that evolutionarily stable dispersal rates should increase with the frequency of local extinctions. Most metapopulation models assume site saturation (i.e., no local population dynamics), yet the majority of species distributed as metapopulations rarely attain carrying capacity in all occupied patches. In this article, we relax this assumption and examine the evolutionarily stable dispersal rate under nonsaturated but still competitive demographic conditions. Contrary to previous predictions, we show that increasing local extinction rates may allow decreasing dispersal rates to evolve.

Local Extinction and the Evolution of Dispersal Rates: Causes and Correlations

“…1). For extinc- tion rates up to approximately , our E p 0.1/generation results are in good agreement with the predictions of Ronce et al (2000a). However, if E is further increased, the mean persistence time of the metapopulation declines dramatically, and none of our metapopulations persisted for 10,000 generations.…”

“…Recently, Ronce et al (2000a) and Parvinen et al (2003) have challenged this simple view of the relationship between local extinction rate and ES dispersal rate. They suggest that, under some conditions, ES dispersal rates may in fact decrease as local extinction rates decrease.…”

“…Since the number of empty patches should increase with increasing extinction rate, a number of studies have been devoted to the relationship between local extinction rates and individual dispersal rates (for a review, see Ronce et al 2000a). Most of them show that we should expect evolutionarily stable (ES) dispersal rates to increase with local extinction rates (e.g., Comins et al 1980;Olivieri et al 1995).…”

Joint evolution of altruistic cooperation and dispersal in a metapopulation of small local populations

“…Indeed we observe from Figure 4, that increasing the catastrophe rate has an increasing effect on dispersal. Note, however, that also non-monotonic dependence of evolutionarily stable dispersal rates on catastrophes have been observed (Ronce et al, 2000;Gyllenberg et al, 2002;Parvinen et al, 2003;Parvinen, 2006). Once catastrophes are very frequent, most individuals reside in thinly populated patches anyway, and thus benefits of dispersal can decline.…”

“…Temporal heterogeneity has been shown to be a mechanism promoting dispersal, because it results in sparsely populated patches, into which immigration typically is beneficial. Such temporal heterogeneity can result, e.g., from non-equilibrium local population dynamics (Doebeli, 1995;Holt and McPeek, 1996;Doebeli and Ruxton, 1997;Parvinen, 1999) or catastrophes (Ronce et al, 2000;Gyllenberg and Metz, 2001;Gyllenberg et al, 2002;Parvinen, 2002Parvinen, , 2006. In case of small local populations, local population dynamics is necessarily stochastic resulting in temporal heterogeneity, which together with kin selection promotes dispersal Parvinen et al, 2003;Parvinen and Metz, 2008;Parvinen et al, 2012).…”