Molecular biogeography and diversification of the endemic terrestrial fauna of the Hawaiian Islands

Abstract

Oceanic islands have played a central role in biogeography and evolutionary biology. Here, we review molecular studies of the endemic terrestrial fauna of the Hawaiian archipelago. For some groups, monophyly and presumed single origin of the Hawaiian radiations have been confirmed (achatinelline tree snails, drepanidine honeycreepers, drosophilid flies, Havaika spiders, Hylaeus bees, Laupala crickets). Other radiations are derived from multiple colonizations (Tetragnatha and Theridion spiders, succineid snails, possibly Dicranomyia crane flies, Porzana rails). The geographic origins of many invertebrate groups remain obscure, largely because of inadequate sampling of possible source regions. Those of vertebrates are better known, probably because few lineages have radiated, diversity is far lower and morphological taxonomy permits identification of probable source regions. Most birds, and the bat, have New World origins. Within the archipelago, most radiations follow, to some degree, a progression rule pattern, speciating as they colonize newer from older islands sequentially, although speciation often also occurs within islands. Most invertebrates are single-island endemics. However, among multi-island species studied, complex patterns of diversification are exhibited, reflecting heightened dispersal potential (succineids, Dicranomyia). Instances of Hawaiian taxa colonizing other regions are being discovered (Scaptomyza flies, succineids). Taxonomy has also been elucidated by molecular studies (Achatinella snails, drosophilids). While molecular studies on Hawaiian fauna have burgeoned since the mid-1990s, much remains unknown. Yet the Hawaiian fauna is in peril: more than 70 per cent of the birds and possibly 90 per cent of the snails are extinct. Conservation is imperative if this unique fauna is to continue shedding light on profound evolutionary and biogeographic questions.

Twenty Years of Molecular Biogeography in the West Mediterranean Islands of Corsica and Sardinia: Lessons Learnt and Future Prospects

“…Multiple lineages of Canarian reptiles were established via independent episodes of colonization, while darkling beetles, brimstone butterflies and fruit flies reached the archipelago only once [52]. Some representatives of the extant terrestrial fauna of the remote archipelagos of Hawaii and Galàpagos, perhaps the best studied oceanic insular settings, derives from single colonizing episodes while for others molecular data do not justify such an assumption [47,53]. Groups with a monophyletic origin include some evolutionary paradigms such as the Hawaiian drosophilids and honeycreepers and the Galàpagos giant tortoises and Darwin's finches.…”

Investigating the origin of vagrant dusky groupers, Epinephelus marginatus (Lowe, 1834), in coastal waters of Réunion Island

“…Understanding cases of colonization of isolated volcanic islands through long distance dispersal provides insight into founding events and diversification that are fundamental processes underlying oceanic island endemism (Cowie & Holland, 2008;Parent et al, 2008). These oceanic islands are often distant from large land masses and the chance of colonization and subsequent divergence of populations is dependent on several biological and physical factors.…”

The Generation of a Biodiversity Hotspot: Biogeography and Phylogeography of the Western Indian Ocean Islands

“…The discipline has provided many elegant examples of the evolutionary mechanisms involved in generating biodiversity, especially the interplay of geological processes and colonization and isolation (Emerson 2008;Gillespie, Claridge, and Goodacre 2008;Parent, Caccone, and Petren 2008;Ricklefs and Bermingham 2008). Islands have provided particularly strong insights into adaptive radiations (Camacho-Garcia and Gosliner 2008;Blackledge and Gillespie 2004;Cowie and Holland 2008;Gillespie and Roderick 2002;Losos and DeQueiroz 1997;Schluter 2000), the processes of colonization and extinction Goldberg, Lancaster, and Ree 2011), the formation of species (Emerson 2008;Pickford et al 2008;Gillespie and Roderick 2002;Schluter and Nagel 1995;Vences et al 2009), and convergent evolution and formation of ecomorphs (Bossuyt and Milinkovitch 2000;Gillespie 2004Gillespie , 2005Losos 1988;Wildman et al 2007;Burridge 2000;Rothe et al 2011). Naturally, islands have also played a key role in revealing the causes and consequences of long distance dispersal, in particular, the ecological and evolutionary consequences of varying dispersal propensities of different lineages, and the evolutionary changes in dispersal propensity, such as the loss of dispersal ability following island colonization Holland 2006, 2008;Hedges and Heinicke 2007;Holland and Cowie 2006;Byrne et al 2011;Bell et al 2005;Darwin 1909;Clark 1994;Gillespie et al 2012).…”