Old Evidence
Ancient Rapanui genomes reveal resilience and pre-European contact with the Americas
Víctor Moreno-Mayar et al.
Nature, 12 September 2024, Pages 389-397
Abstract:
Rapa Nui (also known as Easter Island) is one of the most isolated inhabited places in the world. It has captured the imagination of many owing to its archaeological record, which includes iconic megalithic statues called moai. Two prominent contentions have arisen from the extensive study of Rapa Nui. First, the history of the Rapanui has been presented as a warning tale of resource overexploitation that would have culminated in a major population collapse -- the ‘ecocide’ theory. Second, the possibility of trans-Pacific voyages to the Americas pre-dating European contact is still debated. Here, to address these questions, we reconstructed the genomic history of the Rapanui on the basis of 15 ancient Rapanui individuals that we radiocarbon dated (1670–1950 CE) and whole-genome sequenced (0.4–25.6×). We find that these individuals are Polynesian in origin and most closely related to present-day Rapanui, a finding that will contribute to repatriation efforts. Through effective population size reconstructions and extensive population genetics simulations, we reject a scenario involving a severe population bottleneck during the 1600s, as proposed by the ecocide theory. Furthermore, the ancient and present-day Rapanui carry similar proportions of Native American admixture (about 10%). Using a Bayesian approach integrating genetic and radiocarbon dates, we estimate that this admixture event occurred about 1250–1430 CE.
Pervasive findings of directional selection realize the promise of ancient DNA to elucidate human adaptation
Ali Akbari et al.
Harvard Working Paper, September 2024
Abstract:
We present a method for detecting evidence of natural selection in ancient DNA time-series data that leverages an opportunity not utilized in previous scans: testing for a consistent trend in allele frequency change over time. By applying this to 8433 West Eurasians who lived over the past 14000 years and 6510 contemporary people, we find an order of magnitude more genome-wide significant signals than previous studies: 347 independent loci with >99% probability of selection. Previous work showed that classic hard sweeps driving advantageous mutations to fixation have been rare over the broad span of human evolution, but in the last ten millennia, many hundreds of alleles have been affected by strong directional selection. Discoveries include an increase from ~0% to ~20% in 4000 years for the major risk factor for celiac disease at HLA-DQB1; a rise from ~0% to ~8% in 6000 years of blood type B; and fluctuating selection at the TYK2 tuberculosis risk allele rising from ~2% to ~9% from ~5500 to ~3000 years ago before dropping to ~3%. We identify instances of coordinated selection on alleles affecting the same trait, with the polygenic score today predictive of body fat percentage decreasing by around a standard deviation over ten millennia, consistent with the Thrifty Gene hypothesis that a genetic predisposition to store energy during food scarcity became disadvantageous after farming. We also identify selection for combinations of alleles that are today associated with lighter skin color, lower risk for schizophrenia and bipolar disease, slower health decline, and increased measures related to cognitive performance (scores on intelligence tests, household income, and years of schooling). These traits are measured in modern industrialized societies, so what phenotypes were adaptive in the past is unclear. We estimate selection coefficients at 9.9 million variants, enabling study of how Darwinian forces couple to allelic effects and shape the genetic architecture of complex traits.
Historical and archaeogenomic identification of high-status Englishmen at Jamestown, Virginia
Douglas Owsley et al.
Antiquity, August 2024, Pages 1040-1054
Abstract:
The authors report on ancient DNA data from two human skeletons buried within the chancel of the 1608–1616 church at the North American colonial settlement of Jamestown, Virginia. Available archaeological, osteological and documentary evidence suggest that these individuals are Sir Ferdinando Wenman and Captain William West, kinsmen of the colony's first Governor, Thomas West, Third Baron De La Warr. Genomic analyses of the skeletons identify unexpected maternal relatedness as both carried the mitochondrial haplogroup H10e. In this unusual case, aDNA prompted further historical research that led to the discovery of illegitimacy in the West family, an aspect of identity omitted, likely intentionally, from genealogical records.
Neandertal burial practices in Western Asia: How different are they from those of the early Homo sapiens?
Ella Been & Omry Barzilai
L'Anthropologie, July-August 2024
Abstract:
The Middle Paleolithic of Western Asia is one of the more composite time periods in human evolution as it hosted at least two hominin species -- early Homo sapiens and Neandertals. The early Homo sapiens originated from Africa whereas Neandertals arrived from Europe. In the Levant, these populations explored the same geographical niches, utilized similar resources, and may even inhabited the same caves. While the biological and morphological evidence discriminate between the two hominin populations, the material culture does not. Middle Paleolithic Neandertals and Homo sapiens used the same knapping methods to make their formal stone tools (i.e., Levallois core technology). This unique scenario hypothetically proposes that the two species shared one material culture. In the current research, we examine this hypothesis through studying the burial practices of these two distinct populations and comparing biological and cultural data from primary grave contexts. Examined anthropological and cultural variables show similar behavior in some respects such as body position, gender, age at death or burial offerings/goods, but also exhibit differences in location of burials within the caves, choice of different grave goods, and special positional markers. The analyzed data propose the two populations share some cultural behavior from the origin territory (Europe, Africa). Nevertheless, Middle Paleolithic Levantine burials are earlier than Neandertal burials in Europe and from Homo sapiens burials in Africa. Accordingly, we conclude the custom of human burials was innovated in the Levant from where it spread to the Neandertal territorial range in Europe. The arrival of Homo sapiens and Neandertal populations to the Levant between MIS 5 and MIS 3 likely influenced territorial dynamics. A compelling indicator of land ownership is evident in the widespread practice of burials by both populations. We hypothesize that the growing frequency of burials by these two populations in Western Asia is linked to the intensified competition for resources and space resulting from the arrival of these populations.
Early archaeological evidence of wheat and cotton from medieval Ile-Ife, Nigeria
Amanda Logan et al.
Proceedings of the National Academy of Sciences, 10 September 2024
Abstract:
This study reports the earliest directly dated occurrence of archaeological wheat and cotton in the humid forests of West Africa. These are the first archaeobotanical results from the medieval urban center of Ile-Ife, southwestern Nigeria, best known for its famous artworks. Both wheat and cotton likely spread through trans-Saharan trade networks that laid the foundation for later European trade systems. Forty-eight (48) grains of free-threshing wheat (Triticum aestivum/durum) represent the largest assemblage of wheat recovered in sub-Saharan West Africa, which is surprising given that wheat cannot be cultivated locally. Larger quantities of cotton (Gossypium sp.) recovered from late 12th- to early 13th-century CE contexts suggest earlier and more widespread use than wheat. Cotton may have been cultivated and manufactured into cloth locally. The quick adoption of these exotic crops illustrates the active negotiation of prestige through culinary and adornment practices, as well as a high degree of agricultural experimentation.
Bioarchaeology and evidence of violence from a precolonial later stone age communal burial in South Africa
Calvin Mole et al.
PLoS ONE, September 2024
Abstract:
This study reports on the bioarchaeology and evidence of interpersonal violence in a group of archaeological skeletons found near Ladismith, Western Cape, South Africa. The co-mingled skeletal remains derive from at least ten individuals of varying ages and both sexes. Overlapping radiocarbon dates on three individuals place them in the first half of the 15th century CE, pre-dating first European contact at the end of that century. Three juvenile crania have perimortem perforations, the locations of which indicate violent deaths. The sizes and shapes of the lesions suggest impact by a blade at least 110mm long and 50mm wide but with edges only 2mm thick. Based on these dimensions, we hypothesise that this was a metal-tipped spear. The nearest metal-working communities at this time lived approximately 500 km away, implying long-distance trade or exchange. δ13C, δ15N and 87Sr/86Sr values indicate that this was a heterogenous group of individuals who had spent their early lives in different locations and consumed varied diets, who had come together and were living in or travelling through the Ladismith area at the time of their deaths. This finding extends the timeframe and location for the practice of communal burial in the Holocene of southern Africa and provides additional support for the hypothesis that communal burials in this region tend to be associated with violence.