Caribbean biogeography: molecular evidence for dispersal in West Indian terrestrial vertebrates.

Abstract

The geological association of the Greater Antilles with North and South America in the late Cretaceous led to the hypothesis that the present Antillean biota reflects those ancient land connections. Molecular data from diverse West Indian amphibians and reptiles and their mainland relatives support a more recent derivation of the Antillean vertebrate fauna by overwater dispersal. The catastrophic bolide impact in the Caribbean region at the close of the Cretaceous provides a proximate cause for the absence of an ancient West Indian biota.

Cenozoic biogeography and evolution in direct-developing frogs of Central America (Leptodactylidae: Eleutherodactylus) as inferred from a phylogenetic analysis of nuclear and mitochondrial genes

“…This calibration overlaps with HedgesÕ (1996) estimate of 77-63 mya for the origin of Eleutherodactylus in the West Indies. The ancestors of the subgenera Syrrhophus and Euhyas then diverged 46-25 mya, agreeing with a previous estimate of 37 mya (Hedges et al, 1992) and the fossil record (Holman, 1968;Iturralde-Vinent and MacPhee, 1996).…”

“…This ''young Craugastor'' hypothesis has a disadvantage in requiring that the ancestral Craugastor rafted to Central America during the late Eocene. Trans-oceanic dispersal by amphibians is an unlikely phenomenon (Darwin, 1859), but it does happen (Hedges et al, 1992;Vences et al, 2003Vences et al, , 2004. One advantage of a younger Craugastor, however, is that the southern portion of its biogeographic history would be more easily reconciled with the relatively young age of lower Central America (Coates et al, 2004;Whitmore and Stewart, 1965).…”

“…Among these South American frogs came the ancestor of Craugastor, according to this model. With the break-up of the land bridge, the ancestral Euhyas came to occupy the area that would become Cuba (Hedges, 1989;Hedges et al, 1992). These West Indian Eleutherodactylus diverged from their mainland counterparts an estimated 77-63 million years ago (mya) (Hedges, 1996), coinciding with the land-bridge model.…”

Extinction and biogeography in the Caribbean: new evidence from a fossil riodinid butterfly in Dominican amber

“…Three main mechanisms have been proposed to explain the origins of the Antillean fauna: (i) dispersal over water barriers during much of the Tertiary (Hedges et al 1992;Hedges 1996); (ii) continent-island vicariance, with a more-or-less continuous landmass between North and South America, the 'proto-Greater Antilles', beginning to move east into the Caribbean in the Middle Eocene (Rosen 1975(Rosen , 1985; and Each of these mechanisms appears to have been responsible for shaping parts of today's Antillean butterfly fauna, which largely has affinities with South America, and particularly Central America (Miller & Miller 1989). That the Antilles have not been substantially recolonized by riodinids since the hypothesized PleistoceneHolocene extinctions shows that these comparatively sedentary butterflies, which tend to have smaller than average ranges for the Papilionoidea (Hall & Harvey 2002, are not good over-water dispersers (mechanism (i)).…”

Molecular insights into the relationships and biogeography of West Indian anoline lizards

“…If species were separated by the movement of the proto-Antilles with the Caribbean plate in the late Cretaceous; all IDs measured between pairs of taxa in the Caribbean and the mainland were expected to fall between 117-133. This is based upon a standard calibration of the albumin clock, using both fossil and geological information for a number of vertebrate groups, where approximately 100 units of ID accumulate every 55-60 miHion years of lineage separation (Wilson et al, 1977;Maxson, 1992). These comparisons, with alliD value.s measured less than those expected under the vicariance model, refute a vicariant origin for the majority of the present-day West Indianherpetofauna (Hedges et a/., 1992).…”