The Junior Research Group of the DFG Center for Advanced Studies was established in 2015, with Dr. Yonatan Sahle as its leader. The broad research interest of the working group was anatomical and behavioral evolution across the emergence of Homo sapiens. The group worked on later Middle- and Late Pleistocene fossil hominin and archaeological remains from eastern Africa, mainly Ethiopia, Kenya, and Tanzania.
The Junior Research Group had two doctoral students. Abel Bosman (M.Sc., University of Leiden) studied Middle-Late Pleistocene hominin remains from several contexts in eastern Africa. Specifically, he employed advanced techniques in virtual anthropology to reconstruct and analyze these fossils. He reconstructed Pleistocene hominin crania from Kenya and Tanzania. Dr. Hila Ashkenazy (Ph.D, University of Jerusalem) examined lithic assemblages from recently excavated cave sites in southeastern Ethiopia.
In addition to doctoral dissertation projects, the Junior Research Group was actively exploring for new Late Pleistocene paleoanthropological occurrences along the western margin of the Afar Rift, Ethiopia. These multidisciplinary explorations, led by Dr. Yonatan Sahle, involved several collaborators, including the DFG Center’s co-director Prof. Dr. Katerina Harvati. Explorations in parts of the region of interest yielded promising results.
As part of its aim to promote interdisciplinary dialogue, the Junior Research Group organized bi-weekly colloquia in the Center. The aim of these colloquia was to discuss current research in the four areas represented by the Center, thereby serving as a forum for new research ideas and interdisciplinary collaborations. A typical colloquium involved a talk by researchers based in the Center or invited guests, while published works of interest were also critically discussed.
Phenotypic variation in the human mandible over the last 500 years in the Netherlands Applying geometric morphometrics methods to quantify the anatomical variation of the mandible, the primary aim of this project is to assess patterns of phenotypic variation across the last 500 years in the Netherlands. The project, in collaboration with Dan Dediu and Scott Moisik from the Max Planck Institute for Psycholinguistics in Nijmegen, and Andrea Waters-Rist from the Laboratory for Human Osteoarchaeology in Leiden, utilizes 3D laser scan data of two Dutch archaeological populations (Alkmaar, AD 1484-1574 and Middenbeemster, AD 1829-1866) and MRI scan data of extant Dutch individuals.
Virtual reconstruction of African hominin fossils As part of his dissertation, Bosman is working on the reconstruction of two hominin fossil crania from East Africa. The first, Eyasi I, was discovered off the shore of Lake Eyasi, Tanzania in the 1930s and the second, Kabua I, was located in the western shore of Lake Turkana, Kenya in 1959. Both are important in understanding of the evolution and diversity of hominin populations in Africa during the Middle to Late Pleistocene. However, they have remained largely out of discussion and scientific research due to their fragmentary nature. Thus, Bosman uses micro-CT scans of the fossil fragments and a suite of virtual anthropological techniques to reconstruct the crania, providing a starting point for further comparative work and taxonomic assessment. The project is part of a collaboration with Chris Stringer of the National History Museum, London, prospective DFG Center fellow Laura Buck of the University of Cambridge, and colleagues.
Dietary patterns of Pre-Hispanic agriculture in the Americas Together with the Argentinian researchers Adolfo Gil and Eva Peralta (CONICET- Museo de Historia Natural de San Rafael), Menéndez is studying the role of diet on the diversification of prehistoric Central-West Argentinian populations. This project uses isotopic, paleo-pathologic, and skeletal phenotypic data to address the existence of spatial differences among the populations that inhabited Argentina (e.g. Menéndez 2016a and Menéndez 2016b). In collaboration with Gabriel Šaffa (University of Prešov and former Erasmus trainee at the DFG Center), Menéndez analyzes the demographic patterns of isotopic variation for prehistoric Central-West Argentinian populations in order to understand weaning time in hunter-gatherers, agriculturalists, and populations practicing mixed subsistence.
The role of non-random factors in shaping the human skull of South American populations South American populations have been characterized by a high degree of anatomical variation. Menéndez investigates the influence that non-stochastic factors had on the anatomical diversification of late Holocene populations. Toward that end, she is building a database that includes skeletal data of prehistoric southern South American populations alongside ecological data corresponding to the regions they inhabited. Together with Domenico Giusti (University of Tübingen), Menéndez employs spatial statistics techniques as global and local Moran´s I correlograms, interpolation maps, and spatial regressions to assess the spatial variation of anatomical variation in South American populations.
Evolutionary processes in the diversification of South American human populations The peopling of the Americas has been a subject of intense debate for centuries since different disciplines have contributed to diverse hypotheses on the mode and timing of the first settlers in the continent. Menéndez works on comparing the variation of early Holocene and late Holocene populations from different regions of South America (e.g. Menéndez and Lotto 2016). Currently, she is initiating the study of anatomical skeletal data from the Argentinean Pampas that will serve as a baseline for understanding the genetic and phenotypic evolution of populations of the southern cone, with implications on the peopling of the Americas.
Lithic technology of anatomically modern humans What were the technology and behaviors of our species before its ultimately successful global dispersal during the Late Pleistocene? What role did these play in such critical evolutionary events? As it stands, investigating whether complex technological and behavioral innovations triggered/enabled the dispersal of modern humans within and out of Africa requires data from new excavations (as well as nuanced analyses of available assemblages) spanning the Late Pleistocene. In collaboration with Ethiopian-based archaeologist Dr. Yonas Beyene, Dr. Yonatan Sahle currently studies one of the few assemblages in the region found in association with early anatomically modern human fossils. Recent excavations in Late Pleistocene contexts at Halibee (Middle Awash, Ethiopia) have recovered thousands of such artifacts.
Field explorations in the Afar Rift region of Ethiopia In addition to known sites, Sahle is also conducting exploration of additional Late Pleistocene occurrences in the Afar Rift and adjoining escarpments. These explorations promise a more detailed understanding of the context in which technological and behavioral patterns that are considered complex and “enabling” evolved in a region critical to our understanding of modern human origins.
Modern human dispersals Despite growing consensus on the importance of Africa as a source for the emergence of anatomically modern humans, their dispersal out of the continent remains controversial. Using data of extant human populations, as well as fossil specimens, Reyes-Centeno’s research seeks to test competing hypotheses for the dispersal of modern humans out of Africa and into Eurasia (e.g. Reyes-Centeno 2015, Reyes-Centeno 2016a). He continues an active collaboration with Silvia Ghirotto (University of Ferrara and DFG Center fellow) in utilizing genomic and cranial phenotype data to better understand how the fossil record can be reconciled with inferences on modern human history and demography drawn from genomic data.
Bio-cultural evolution and the New Synthesis While the Modern Synthesis of the 20th century sought to integrate the knowledge of various natural history disciplines and to reconcile Mendelian and Darwinian theory, the New Synthesis of 21st century strives to incorporate knowledge and theory from the social sciences and humanities in order to understand the human past. With Katerina Harvati and Gerhard Jäger, Reyes-Centeno explores the association of linguistic and skeletal phenotypic variation of modern human populations (e.g. Reyes-Centeno, Harvati, and Jäger 2016). In collaboration with Silvia Ghirotto and Tsuneiko Hanihara (Kitasato University, Japan), they further explore these associations with genomic variation in order to understand the extent to which languages and genes co-evolve. Inspired by population geneticist Sewall Wright’s foreshadowing of the efforts of a New Synthesis*, Reyes-Centeno seeks to apply quantitative and population genetic methods for the study of biological and cultural change (e.g. Reyes-Centeno 2015).
*In his seminal 1950 essay during the Modern Synthesis “The genetical structure of populations,” Sewall Wright claimed that “…organic evolution is not the only sort of evolution in the sense of a process of cumulative change. When a level of intelligence was reached in an anthropoid line that made symbolic speech possible, a new evolutionary process emerged, enormously more rapid than organic evolution.”
Quantitative and population genetic applications to skeletal and fossil data Paleoanthropologists rely largely on the primate fossil record and skeletal evidence of recent populations to make inferences on the evolutionary history of our species. A central challenge for paleoanthropology (and paleo-biology more generally) is making evolutionary inferences with limited fossil data, particularly when endogenous ancient DNA is unavailable. Reyes-Centeno’s research therefore applies a quantitative genetic approach to the study of skeletal and fossil data, embracing the concept of “paleo-demes” for the hominin fossil record (e.g. Reyes-Centeno 2015, Reyes-Centeno 2016b) and adapting methods developed from molecular biology to the study of skeletal variation (e.g. Reyes-Centeno et al. 2015, 2017).
Virtual anthropology and geometric morphometrics Advances in medical imaging technology and in the quantitative analysis of forms have provided an important toolkit for paleoanthropologists. Reyes-Centeno applies a suite of virtual anthropology methods in his research and is interested in developing new methodological approaches that can aid in understanding human evolutionary history. He currently works on the reconstruction and analysis of the Kabua I and Eyasi I fossils from East Africa, in collaboration with Katerina Harvati, Abel Bosman, Chris Stringer of the National History Museum, London, and prospective DFG Center fellow Laura Buck of the University of Cambridge. He has analyzed the inner ear anatomy of those specimens (Reyes-Centeno et al. 2014), as well as of the Cioclovina specimen (Uhl et al. 2016).