Kevin Lewis

May 21, 2022

The Shadow of the Neolithic Revolution on Life Expectancy: A Double-Edged Sword
Raphael Franck et al.
Brown University Working Paper, March 2022

This research explores the persistent effect of the Neolithic Revolution on the evolution of life expectancy in the course of human history. It advances the hypothesis and establishes empirically that the onset of the Neolithic Revolution and the associated rise in infectious diseases triggered a process of adaptation reducing mortality from infectious diseases while increasing the propensity for autoimmune and inflammatory diseases. Exploiting an exogenous source of variation in the timing of the Neolithic Revolution across French regions, the analysis establishes the presence of these conflicting forces - the beneficial effects on life expectancy before the second epidemiological transition and their adverse effects thereafter. 

Dynamic finite-element simulations reveal early origin of complex human birth pattern
Pierre Frémondière et al.
Communications Biology, April 2022

Human infants are born neurologically immature, potentially owing to conflicting selection pressures between bipedal locomotion and encephalization as suggested by the obstetrical dilemma hypothesis. Australopithecines are ideal for investigating this trade-off, having a bipedally adapted pelvis, yet relatively small brains. Our finite-element birth simulations indicate that rotational birth cannot be inferred from bony morphology alone. Based on a range of pelvic reconstructions and fetal head sizes, our simulations further imply that australopithecines, like humans, gave birth to immature, secondary altricial newborns with head sizes smaller than those predicted for non-human primates of the same body size especially when soft tissue thickness is adequately approximated. We conclude that australopithecines required cooperative breeding to care for their secondary altricial infants. These prerequisites for advanced cognitive development therefore seem to have been corollary to skeletal adaptations for bipedal locomotion that preceded the appearance of the genus Homo and the increase in encephalization. 

In situ evidence for Paleoindian hematite quarrying at the Powars II site (48PL330), Wyoming
Spencer Pelton et al.
Proceedings of the National Academy of Sciences, May 2022

We present results from controlled excavations at the Powars II Paleoindian hematite quarry (48PL330), located in the foothills of the southern Rocky Mountains in Wyoming. We document a deeply buried, bedrock-adjacent stratum containing in situ evidence for hematite quarrying beginning ca. 12,840 to 12,505 calibrated years (cal) B.P. associated with the Clovis and Plainview cultural complexes. Later occupation by the Hell Gap cultural complex intruded within previous quarry tailings and likely dates to ca. 11,600 cal B.P. The earliest Clovis and Plainview occupations contain a diverse assemblage of stone and faunal artifacts indicative of hematite quarrying, weaponry production and repair, and other tasks, while the later Hell Gap occupation is primarily focused on hematite quarrying and the placement of items in piles within an abandoned quarry feature. In situ archaeological deposits at Powars II are distinguished from overlying ex situ strata by sediment characteristics, bone preservation, patina development on chipped stone artifacts, diagnostic weaponry assemblages, and damage to flake margins. Nonlocal chipped stone raw materials indicate ties to much of the North American Great Plains, suggesting that Powars II hematite may be found in sites throughout the American midcontinent. 

Ancient Maltese genomes and the genetic geography of Neolithic Europe
Bruno Ariano et al.
Current Biology, forthcoming

Archaeological consideration of maritime connectivity has ranged from a biogeographical perspective that considers the sea as a barrier to a view of seaways as ancient highways that facilitate exchange. Our results illustrate the former. We report three Late Neolithic human genomes from the Mediterranean island of Malta that are markedly enriched for runs of homozygosity, indicating inbreeding in their ancestry and an effective population size of only hundreds, a striking illustration of maritime isolation in this agricultural society. In the Late Neolithic, communities across mainland Europe experienced a resurgence of hunter-gatherer ancestry, pointing toward the persistence of different ancestral strands that subsequently admixed. This is absent in the Maltese genomes, giving a further indication of their genomic insularity. Imputation of genome-wide genotypes in our new and 258 published ancient individuals allowed shared identity-by-descent segment analysis, giving a fine-grained genetic geography of Neolithic Europe. This highlights the differentiating effects of seafaring Mediterranean expansion and also island colonization, including that of Ireland, Britain, and Orkney. These maritime effects contrast profoundly with a lack of migratory barriers in the establishment of Central European farming populations from Anatolia and the Balkans. 

The spread of herds and horses into the Altai: How livestock and dairying drove social complexity in Mongolia
Alicia Ventresca Miller et al.
PLoS ONE, May 2022

The initial movement of herders and livestock into the eastern steppe is of great interest, as this region has long been home to pastoralist groups. Due to a paucity of faunal remains, however, it has been difficult to discern the timing of the adoption of domesticated ruminants and horses into the region, though recent research on ancient dairying has started to shed new light on this history. Here we present proteomic evidence for shifts in dairy consumption in the Altai Mountains, drawing on evidence from sites dating from the Early Bronze to the Late Iron Age. We compare these finds with evidence for the rise of social complexity in western Mongolia, as reflected in material remains signaling population growth, the establishment of structured cemeteries, and the erection of large monuments. Our results suggest that the subsistence basis for the development of complex societies began at the dawn of the Bronze Age, with the adoption of ruminant livestock. Investments in pastoralism intensified over time, enabling a food production system that sustained growing populations. While pronounced social changes and monumental constructions occurred in tandem with the first evidence for horse dairying, ~1350 cal BCE, these shifts were fueled by a long-term economic dependence on ruminant livestock. Therefore, the spread into the Mongolian Altai of herds, and then horses, resulted in immediate dietary changes, with subsequent social and demographic transformations occurring later. 

A Middle Pleistocene Denisovan molar from the Annamite Chain of northern Laos
Fabrice Demeter et al.
Nature Communications, May 2022

The Pleistocene presence of the genus Homo in continental Southeast Asia is primarily evidenced by a sparse stone tool record and rare human remains. Here we report a Middle Pleistocene hominin specimen from Laos, with the discovery of a molar from the Tam Ngu Hao 2 (Cobra Cave) limestone cave in the Annamite Mountains. The age of the fossil-bearing breccia ranges between 164–131 kyr, based on the Bayesian modelling of luminescence dating of the sedimentary matrix from which it was recovered, U-series dating of an overlying flowstone, and U-series–ESR dating of associated faunal teeth. Analyses of the internal structure of the molar in tandem with palaeoproteomic analyses of the enamel indicate that the tooth derives from a young, likely female, Homo individual. The close morphological affinities with the Xiahe specimen from China indicate that they belong to the same taxon and that Tam Ngu Hao 2 most likely represents a Denisovan.


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