1Committee on Evolutionary Biology, University of Chicago, 2Department of Anthropology, The Field Museum, 3Department of Anthropology, University of Illinois at Urbana-Champaign
April 16, 2016 8:30, A 602
Island dwarfing, whereby large-bodied organisms evolve smaller body size on islands because food resources are limited, has been widely studied. But time of colonization and intraspecific relatedness have rarely been taken into account. Relatedness is especially important when studying island dwarfing because evolution occurs within species or between closely related species. Here, we report the successful use of next generation techniques to sequence mitogenomes of 120 Southeast Asian longtailed macaque (Macaca fascicularis) specimens ranging between 50 and 100+ years old, housed at natural history museums around the world. These sequences, at an average of 45x coverage, have been used to reconstruct intraspecific phylogenies of M. fascicularis throughout the Southeast Asian mainland and islands using both maximum-likelihood and Bayesian analyses, which yielded almost identical results. Calibration of the phylogeny indicates that colonization of the Sunda islands began over 1.5 Ma, as previously found, but that colonization of various oceanic islands, including the Philippines, was much more recent, on the order of thousands of years. Additionally, we used this phylogeny to take relatedness amongst individuals into account when analyzing body size and brain size data from these museum specimens. Without phylogenetic correction, M. fascicularis does not display dwarfing in either body size or brain size. When phylogeny is taken into account, we see a trend in body size dwarfing on islands but still not in brain size. These results reveal the importance of taking intraspecific phylogenetics into account when conducting comparative studies, especially when studying island organisms.