Abstract # 44:

Scheduled for Saturday, August 26, 2017 06:00 PM-08:00 PM: (National Ballroom AB) Poster Presentation


M. C. Mareno1, S. J. Schapiro1, R. D. Latzman2, C. C. Sherwood3 and W. D. Hopkins4,5
1University of Texas MD Anderson Cancer Center, 650 Cool Water Drive, Bastrop, Texas 78602, USA, 2Department of Psychology, Georgia State University, Atlanta, Georgia 30302, 3Department of Anthropology, Center for the Advanced Study of Hominid Paleobiology and GW Institute for Neuroscience, The George Washington University, Washington, DC 20052, 4Neuroscience Institute, Georgia State University, Atlanta, Georgia 30302, 5Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, Georgia 30043
     Manufacturing and employing effective tools involves complex motor and cognitive functions that likely evolved in humans along with increased brain size and specialization. Aside from humans, chimpanzees exhibit unrivaled complexity and diversity in tool use form and function. Studies show notable variety within and across wild chimpanzee communities, and captive studies show tool use performance to be highly heritable. Here, we investigated the neural and genetic bases for tool use performance. We obtained MRI scans and tested 201 chimpanzees on a probing task to determine tool use skill. We used source-based morphometry (SBM) to identify structural co-variation of gray matter volume and determine their potential associations with tool use skill. Independent component analysis identified 19 independent gray matter components. After controlling for age, sex and rearing history, two of the SBM components correlated with tool use performance, namely the primary visual cortex (partial r=.209, p=.002) and inferior parietal cortex (partial r=.218, p=.002). Using quantitative genetics, we found significant genetic correlations between tool use performance and the visual cortex (rhog=.756, p<.05) and inferior parietal lobe (rhog=.920, p<.04). Our results indicate common genetic mechanisms involved in tool use and gray matter co-variation, particularly in the visual and inferior parietal cortex. These, as yet unknown genes, may have been selected for in primate evolution and account for the expansion in tool making and use skills observed in humans.