Traces of the Past
The age of the opening of the Ice-Free Corridor and implications for the peopling of the Americas
Jorie Clark et al.
Proceedings of the National Academy of Sciences, 21 March 2022
Abstract:
The Clovis-first model for the peopling of the Americas by ∼13.4 ka has long invoked the Ice-Free Corridor (IFC) between the retreating margins of the Cordilleran and Laurentide ice sheets as the migration route from Alaska and the Yukon down to the Great Plains. Evidence from archaeology and ancient genomics, however, now suggests that pre-Clovis migrations occurred by at least ∼15.5 to 16.0 ka or earlier than most recent assessments of the age of IFC opening at ∼14 to 15 ka, lending support to the use of a Pacific coast migration route instead. Uncertainties in ages from the IFC used in these assessments, however, allow for an earlier IFC opening which would be consistent with the availability of the IFC as a migration route by ∼15.5 to 16.0 ka. Here, we use 64 cosmogenic (10Be) exposure ages to closely date the age of the full opening of the IFC at 13.8 ± 0.5 ka. Our results thus clearly establish that the IFC was not available for the first peopling of the Americas after the Last Glacial Maximum, whereas extensive geochronological data from the Pacific coast support its earlier availability as a coastal migration route.
GWAS on birth year infant mortality rates provides evidence of recent natural selection
Yuchang Wu et al.
Proceedings of the National Academy of Sciences, 14 March 2022
Abstract:
Following more than a century of phenotypic measurement of natural selection processes, much recent work explores relationships between molecular genetic measurements and realized fitness in the next generation. We take an innovative approach to the study of contemporary selective pressure by examining which genetic variants are “sustained” in populations as mortality exposure increases. Specifically, we deploy a so-called “regional GWAS” (genome-wide association study) that links the infant mortality rate (IMR) by place and year in the United Kingdom with common genetic variants among birth cohorts in the UK Biobank. These cohorts (born between 1936 and 1970) saw a decline in IMR from above 65 to under 20 deaths per 1,000 live births, with substantial subnational variations and spikes alongside wartime exposures. Our results show several genome-wide significant loci, including LCT and TLR10/1/6, related to area-level cohort IMR exposure during gestation and infancy. Genetic correlations are found across multiple domains, including fertility, cognition, health behaviors, and health outcomes, suggesting an important role for cohort selection in modern populations.
Multiple lines of evidence of early goose domestication in a 7,000-y-old rice cultivation village in the lower Yangtze River, China
Masaki Eda et al.
Proceedings of the National Academy of Sciences, 7 March 2022
Abstract:
Poultry are farmed globally, with chicken (Gallus gallus domesticus) being the leading domesticated species. Although domestic chicken bones have been reported from some Early Holocene sites, their origin is controversial and there is no reliable domestic chicken bone older than the Middle Holocene. Here, we studied goose bones from Tianluoshan—a 7,000-y-old rice cultivation village in the lower Yangtze River valley, China—using histological, geochemical, biochemical, and morphological approaches. Histological analysis revealed that one of the bones was derived from a locally bred chick, although no wild goose species breed in southern China. The analysis of oxygen-stable isotope composition supported this observation and further revealed that some of the mature bones were also derived from locally bred individuals. The nitrogen-stable isotope composition showed that locally bred mature birds fed on foods different from those eaten by migrant individuals. Morphological analysis revealed that the locally bred mature birds were homogenous in size, whereas radiocarbon dating clearly demonstrated that the samples from locally bred individuals were ∼7,000 y old. The histological, geochemical, biochemical, morphological, and contextual evidence suggest that geese at Tianluoshan village were at an early stage of domestication. The goose population appears to have been maintained for several generations without the introduction of individuals from other populations and may have been fed cultivated paddy rice. These findings indicate that goose domestication dates back 7,000 y, making geese the oldest domesticated poultry species in history.
Residue analysis evidence for wine enriched with vanilla consumed in Jerusalem on the eve of the Babylonian destruction in 586 BCE
Ayala Amir et al.
PLoS ONE, March 2022
Abstract:
The article presents results of residue analysis, based on Gas Chromatograph Mass Spectrometer (GC-MS) measurements, conducted on 13 ceramic storage jars unearthed in the Babylonian destruction layer (586 BCE) in Jerusalem. Five of the jars bear rosette stamp impressions on their handles, indicating that their content was related to the kingdom of Judah’s royal economy. The identification of the original contents remains is significant for the understanding of many aspects related to the nutrition, economy and international trade in the ancient Levant. The study shed light on the contents of the jars and the destruction process of the buildings in which they were found. The jars were used alternatively for storing wine and olive oil. The wine was flavored with vanilla. These results attest to the wine consumption habits of the Judahite elite and echo Jerusalem’s involvement in the trans-regional South Arabian trade of spices and other lucrative commodities on the eve of its destruction by Nebuchadnezzar.
The intrusive nature of the Châtelperronian in the Iberian Peninsula
Joseba Rios-Garaizar et al.
PLoS ONE, March 2022
Abstract:
Multiple factors have been proposed to explain the disappearance of Neandertals between ca. 50 and 40 kyr BP. Central to these discussions has been the identification of new techno-cultural complexes that overlap with the period of Neandertal demise in Europe. One such complex is the Châtelperronian, which extends from the Paris Basin to the Northern Iberian Peninsula between 43,760–39,220 BP. In this study we present the first open-air Châtelperronian site in the Northern Iberian Peninsula, Aranbaltza II. The technological features of its stone tool assemblage show no links with previous Middle Paleolithic technology in the region, and chronological modeling reveals a gap between the latest Middle Paleolithic and the Châtelperronian in this area. We interpret this as evidence of local Neandertal extinction and replacement by other Neandertal groups coming from southern France, illustrating how local extinction episodes could have played a role in the process of disappearance of Neandertals.