ABSTRACT
The majority of marine fauna have a planktonic larval phase potentially able to drift for hundreds to thousands of kilometres before settling out of the water column (Palumbi, 1992). Typically, the populations of these species are large and the fecundities very high, numbering in the millions of eggs per adult female (Palumbi, 1992). Speciation of such taxa is poorly understood since these attributes should lead to high gene flow that would slow the process of species formation. However, marine faunal groups are typically speciose with complex patterns of phylogenetic partitioning. A central question in marine evolutionary biology is: what forces promote speciation in the marine environment?
