ORIGINAL ARTICLE: Eyes wide shut: can hypometabolism really explain the primate colonization of Madagascar?

• Published in: Journal of Biogeography
• Main Authors: Masters, J. C., Lovegrove, B. G., De Wit, M. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2006
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1111/j.1365-2699.2006.01569.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2699.2006.01569.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2699.2006.01569.x

Abstract Aim We investigate the hypothesis that it was the capacity for torpor or hibernation that enabled the lemuriforms (and possibly other mammal groups, e.g. tenrecs and rodents) to invade Madagascar by means of over‐water dispersal. Location Madagascar, East Africa and the Mozambique Channel. Methods We consider the body weights and life‐style features of living primate taxa that employ heterothermy. Using this information as a standard for comparison, we summarize the available information on the Palaeogene strepsirrhine radiation (i.e. members of the infraorder Adapiformes, the extinct sister‐taxon to the lemuriforms, as well as putative stem lemuriforms), particularly with respect to possible trends in body weight among early, middle and late Eocene adapiforms. We discuss Eocene climatic conditions in the northern hemisphere and Africa, and assess the likelihood of adaptations for heterothermy in adapiforms. Finally, we estimate the body weights of the common ancestors to the living Lemuriformes and Lemuroidea using the method of phylogenetically independent contrasts. Results The mean body weights estimated for the early, middle and late Eocene strepsirrhine faunas remain at approximately 2 kg, outside of the range of living primates using heterothermy. The adapiforms’ appearance coincided with the ‘initial Eocene thermal maximum’, an unusually hot period of global warming, and their demise corresponded with a major cooling event coincident with the appearance of ice sheets on Antarctica. They show no evidence of having evolved adaptations that allowed them to withstand climatic deterioration. The body weights of the ancestral lemuriform and ancestral lemuroid are of a similar order to the mean body weight estimated for the adapiforms, i.e. approximately 1.8 and 2.1 kg, respectively. Main conclusions The available evidence argues against the widespread use of heterothermy by adapiforms. The adapiform–lemuriform divergence may have been the result of the lemuriforms adapting to the drier and more ...