1Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 2Department of Physical Anthropology, Penn Museum, University of Pennsylvania, 3Center for Functional Anatomy and Evolution, John Hopkins University School of Medicine
March 28, 2019 3:00, CC Room 26 C
A fundamental consideration in human evolution is the relationship between genetics, environment, and morphological plasticity in producing phenotypic change. Ancient DNA, combined with information about the genetic basis of anthropometric traits from genome-wide association studies (GWAS), allows us to separate these effects. We analyzed genome-wide data from 1155 individuals (45,000-1000BP), along with measurements from 2178 skeletons (34,000-100 BP) in Europe to investigate the relationship between genetic and phenotypic changes in anthropometric traits. Using GWAS summary statistics, we make genetic predictions of phenotype (height, sitting height, leg length, BMI, and bone mineral density) and compare them with observed data. In general, measured changes follow–but are more extreme than–those predicted by genetics. We show that the decrease in stature from the Early Upper Paleolithic to the Neolithic is predicted by genetics. Genetic sitting height remains constant, consistent with the observation that change in stature is driven mainly by changes in leg, not torso, length. Genetic heel bone mineral density decreases sharply between the Mesolithic and Neolithic, as does measured femoral cross-sectional diaphyseal shape–which we interpret as parallel responses to decreases in mobility. Geographically, there is an E-W cline of decreasing stature during the Mesolithic, consistent with genetic predictions. In the Early Upper Paleolithic there is a N-S cline that is not predicted by genetics and may reflect an environmental effect on development. Our results reveal a significant contribution of genetic change–driven by selection, admixture or drift–to phenotypic change, in addition to the consequences of morphological plasticity.
Funding was provided by the Alfred P Sloan Foundation and the Charles E Kaufman Fund of the Pittsburgh Foundation.