Historical divergences associated with intermittent land bridges overshadow isolation by larval dispersal in co-distributed species of Tridacna giant clams

Abstract

Aim: The aim of this study was to test historical and contemporary influences on population structure in the giant clams, Tridacna maxima (Röding, 1798) and T. crocea (Lamarck, 1819). To refine the location of clade boundaries within a newly resurrected species, Tridacna noae (Röding, 1798). Location: Indo-Australian archipelago, including Indonesia, the Philippines, Australia, Papua New Guinea, the Solomon Islands, Republic of Kiribati, the Line Islands and Taiwan. Methods: We used isolation-migration (IMa) coalescent models and distance-based redundancy analyses (dbRDA) to test the relative influence of barriers and continuous distances on historical divergence, gene flow and population st..