Why marine islands are farther apart in the tropics.

Species diversity of benthic marine organisms is highest in tropical archipelagoes. I hypothesize this is in large part a consequence of the temperature dependence of development times and dispersal distances of planktonic larvae. Metabolic theory predicts and empirical studies confirm that marine larvae develop faster and consequently have shorter durations in the plankton at higher temperatures. Metabolic theory can be extended to predict that species diversity of benthic marine organisms is highest in tropical archipelagoes, because warm temperatures limit dispersal and gene flow and isolated islands provide favorable conditions for speciation and coexistence.