Testing for biogeographic mechanisms promoting divergence in Caribbean crickets (genus Amphiacusta)

Abstract

The Caribbean is characterized by a rich and diverse fauna that exhibits high levels of endemism. Numerous attempts have been made over the past several decades to elucidate the means by which this unique fauna emerged (Barbour

A necessarily complex model to explain the biogeography of the amphibians and reptiles of Madagascar

“…Several authors have suggested that the current distribution of biotic diversity in the tropics resulted from a complex interplay of a variety of diversification mechanisms 52,53 . This implies that no single hypothesis adequately explains the diversification of broad taxonomic groups-our results support this assumption.…”

ErechthisKatydids (Tettigoniidae: Conocephalinae) in the Caribbean: New Species from the Bahamas and Hispaniola

“…During the Pleistocene when sea levels were up to 200 m lower, the Great Bahama Bank, made up of present-day Bimini, Andros, New Providence, Eleuthera, the Exumas, Long and Cat Island, was within 15 km of Cuba at its closest point, which likely resulted in the natural movement of many species between these two landmasses (Holzapfel & Harrell 1968, Pregill & Olson 1981, Carew & Mylroie 1997. Cycles of rising sea levels would have resulted in range fragmentation for many species as landmasses became smaller and more separated from one another by ocean, with some populations going extinct while others experienced divergence (Gillespie & Roderick 2002, Glor et al 2005, Oneal et al 2010. In addition to vicariance, dispersal, whether from over-water means or rafting, has also been important in moving organisms around the Caribbean, and thus promoting divergence of populations between islands (Holzapfel & Harrell 1968, Censky et al 1998, Glor et al 2005, Scharer & Epler 2007.…”

“…In addition to vicariance, dispersal, whether from over-water means or rafting, has also been important in moving organisms around the Caribbean, and thus promoting divergence of populations between islands (Holzapfel & Harrell 1968, Censky et al 1998, Glor et al 2005, Scharer & Epler 2007. Cuba represents a centre of origin for many taxa distributed throughout The Greater Antilles, including ants (Morrison 1998), crickets (Oneal et al 2010), lizards (Glor et al 2005) and termites (Scheffrahn et al 2006). Recent extensive sampling for E. gundlachi on Cuba (Yong 2015), and Hispaniola (Perez-Gelabert 2014), did not uncover specimens of E. levyi, which suggests the latter species may be confined to the Bahamas, making it the first endemic katydid known from these islands.…”

Ecological selection as the cause and sexual differentiation as the consequence of species divergence?

“…Phylogenetic analyses show that the diversification history is dominated by inter-island diversification, with closely related species distributed across different islands [10]. Yet, incidences of intra-island speciation (i.e.…”

“…Yet, incidences of intra-island speciation (i.e. sister taxa occur on the same island) raise the question about the role of selection in species divergence, although whether ecological or sexual selection is a cause or consequence of divergence is unclear [10]. The restriction of this highly diverse genus (more than 80 species) to the Caribbean islands, and individual species to wet or dry primary forest, or to damp caves [11], suggests that local adaptation is important.…”