Ancient DNA reveals that few GWAS loci have been strongly selected during recent human history

Genetic data from ancient humans has provided new evidence in the study of loci thought to be under historic selection, and thus is a powerful tool for identifying instances of selection that might be missed by methods that use present-day samples alone. Using a curated set of disease-associated variants from the NHGRI-EBI GWAS Catalog, we provide an analysis to identify disease-associated variants that bear signatures of selection over time. After accounting for the fact that not every ancient individual contributed equally to modern genomes, a Bayesian inference method was used to infer allele frequency trajectories over time and determine which disease-associated loci exhibit signatures of natural selection. Of the 2,709 variants analyzed in this study, 895 show at least a weak signature of selection (|s| > 0.001), including multiple variants that are introgressed from Neanderthals. However, only nine disease-associated variants show a signature of strong selection (|s| > 0.01). Additionally, we find that many risk-associated alleles have increased in frequency during the past 10,000 years. Overall, we find that disease-associated variants from GWAS are governed by nearly neutral evolution. Exceptions to this broad pattern include GWAS loci that protect against asthma and variants in MHC genes. Ancient samples allow us an unprecedented look at how our species has changed over time, and our results represent an important early step in using this new source of data to better understand the evolution of hereditary disease risks.

Lumbosacral Defects in a 16th–18th-Century Joseon Dynasty Skeletal Series from Korea

Paleopathological evidence for congenital and degenerative disorders of the lumbosacral vertebrae is informative about ancient individual lifeways and physical conditions. However, very few studies have focused on the paleopathology of the lumbosacral vertebrae in ancient skeletal series from East Asia. One reason for the lack of studies is that skeletal samples from East Asia are typically insufficient in size to represent populations for comparative studies within the continent. Here, we present the first comprehensive analysis of lumbosacral defects in an East Asian human skeletal sample, examining occurrences of spina bifida occulta (SBO), lumbosacral transitional vertebrae (LSTV), and spondylolysis in remains from Joseon tombs dating to the 16–18th centuries in Korea. In this study, we present an alternative methodology for understanding activities of daily life among ancient Koreans through paleopathological analysis.

Suicide triggers in ancient and recent times

Background: Western medicine has insisted that suicide is always triggered by mental disorder. We have argued that is not the case. Plato (360 BCE) stated that suicide could occur as a response to various predicaments. Aims: To determine whether 1) non-medical suicide triggers could be identified in the stories of ancient times, 2) these suicide triggers remained operative in recent times, and 3) methods of transmission of these models over time (in representations in literature and visual arts) could be identified. Method: We examined history from ancient to the present time, using books, journals and the web, and arranged our findings consistent with our aims. Results: We identified nine (9) ancients who had died in response to non-medical suicide triggers. We were also able to identify at least one recent case, in which the suicide trigger was comparable to that of an ancient individual. Literary and visual art representations of the ancient suicide completer could be identified in every case. Conclusions: Non-medical suicide triggers could be identified in ancient and recent cases. These were various forms of loss, shame/guilt and unavoidable physical pain, reminiscent of the triggers of suicide which Plato found acceptable. It is possible that, consistent with a universal characteristic of life (the avoidance of distress/pain) suicide is an innate response to painful situations, and that the transmission of information about the responses of earlier members has a role in determining the different suicide rates of different cultures.