Lumila Paula Menendez

LUMILA MENÉNDEZ, then a postdoctoral researcher at the Konrad Lorenz Institute for Evolution and Cognition Research, Klosterneuburg, Austria, was awarded a grant in August 2021 to aid research on “Human Morphological Diversification in the Southern Cone: implications for the peopling of South America”. This project aimed to investigate the diversification of ancient human populations in the southern cone of South America, with implications for understanding the peopling of the Americas. To achieve this objective, the study employed tomographies of over 200 ancient individuals from various regions in Argentina, spanning the early to late Holocene periods. Approximately 150 micro-CT scans of petrous bones and 60 medical CT-scans of skulls were generated to examine inner ear variation. The inner ear, or bony labyrinth, was chosen for analysis due to its preservation of a robust phylogenetic signal, attributed to its ossification in utero and minimal developmental plasticity or remodeling in adulthood. Preliminary findings indicate that the variation on the bony labyrinth is notably influenced by non-stochastic evolutionary processes, with the pattern correlating with geographical distances among samples. Furthermore, leveraging micro-CT scanned samples with associated chromosomal sex information, the project explored whether morphological variation in the bony labyrinth is sexually dimorphic, offering potential insights into biological sex. Initial results reveal a general grouping of samples in accordance with chromosomal sex obtained through genetic analysis. These promising outcomes have significant implications for enhancing human identification in forensic investigations and establishing phylogenetic relationships in biological anthropology, particularly when avoiding destructive sampling.