ABSTRACT
In research on the population genetics of marine decapod crustaceans it is often assumed that planktonic larvae disperse widely and genetic markers are not strongly influenced by natural selection. Although population genetic surveys often seem to corroborate these assumptions, some have revealed genetic differentiation among populations that lack discernable barriers to dispersal. These cases, along with insights from related areas of investigation, suggest it may be time to revise our thinking. We now know that dispersal of meroplanktonic larvae can be strongly limited by oceanographic processes and larval behavior. There is also evidence suggesting that directional selection may be stronger in marine populations than previously thought. These new perspectives have important implications for decapod population genetics and phylogeography. This paper will review the findings that have led to a revised view of larval dispersal and will examine natural selection as a potential modifier of dispersal and influence on genetic population structure in decapod crustaceans.
1 INTRODUCTION
