Where were the Indo-Europeans From? Sapienza Participated in the Largest Study on the Ancient DNA of Central and Southern Asian Populations

The vastest research on human DNA ever performed and the first genome of an individual from the Ancient Indus Valley Civilisation reveal an unprecedented fact: the changing descent of Central and Southern Asian populations over time. Twenty-two percent of the newly sequenced genomes have been extracted from the skeletal materials of 116 individuals belonging to Sapienza collections

The vastest research on human DNA ever performed and the first genome of an individual from the Ancient Indus Valley Civilisation reveal an unprecedented fact: the changing descent of Central and Southern Asian populations over time. The study also provides answers to long-standing questions on the origins of agriculture and the source of Central and Southern Asian Indo-European languages.

Geneticists, archaeologists and anthropologists from North America, Europe and Central and Southern Asia have analysed the genomes of the remains of 524 ancient individuals that had never been analysed before, increasing the global total of public-domain ancient genomes by 25%.

By comparing these genomes both amongst themselves and with other already sequenced genomes, as well as by putting the information in the context of our archaeological, linguistic and historical knowledge, the researchers were able to finetune many key details on the individuals who lived in that vast region from the Mesolithic (ca. 12,000 years ago) to the Iron Age (ca. 2000 years ago) and their relations with the region’s current day inhabitants.

Sapienza University contributed to the study with the skeletal materials of 116 individuals that correspond to 22% of the newly sequenced genomes. The remains came from various areas. The largest part of skeletal remains came from Pakistan - 91 individuals from 5 necropolises covering an arc of time spanning from the Final Bronze Age to the Historical Period – but remains also came from Bronza Age Iranian sites. These collections are currently part of the Sapienza Anthropology Museum directed by Giorgio Manzi and the Biology of Populations Lab directed by Alfredo Coppa from the Sapienza Department of Environmental Biology and one of the authors of the article published on Science.

The study employed new sampling methodologies that maximise the possibility of obtaining genetic data from regions in which DNA conservation is often scant. Moreover, the combination of data, methods and academic interpretations has revealed both interactions amongst populations and anomalous values within populations. This, in turn, allowed the researchers to trace two of the most profound cultural transformations that took place in Ancient Eurasia: the shift from hunting-gathering to agriculture and the diffusion of Indo-European languages that today are spoken from the British Isles to Southern Asia.

The Indo-European language family – including Hindi/Urdu, Bengalese, Punjabi, Persian, Russian, English, Spanish, Gaelic and 400 others – is the largest on Earth and, for decades, specialists debated how they were circulated to the most distant corners of the Earth. The study now provides consistent proof of the arrival of Indo-European languages in Europe thanks to shepherds from the Eurasian steppe, disproving the so-called Anatolian Hypothesis and explaining the linguistic characteristics that are shared by branches of the Indo-European language family that are separated by vast geographical distances. For example, genetic models connect speakers of the Indo-European Hindu-Iranian and Baltic-Slavic branches, as current speakers of both branches descend from a subgroup of steppe shepherds that moved west towards Europe nearly 5000 years ago and then also moved east into Central and Southern Asia in the subsequent 1500 years.

The results of this study are also of interest in another long-standing debate: the shift from a hunting-gathering economy to one based on agriculture. The explanation for this has always teetered between migrations, copied ideas and local inventions. Now, the study confirms that the diffusion of agriculture journeyed not only westward from Anatolia to Europe, but also eastward from Anatolia to the Asian regions that were previously inhabited by hunter-gatherers.

Methodological Note: Open-notebook

Most of the data used for the Science study was publicly released about a year and a half ago, when the article was submitted to a pre-press service to allow other researchers to discuss the conclusions and achieve further intuitions.

The publication of the article’s first presentation was met with great interest and the study was the most downloaded pre-press article of 2018 (ca. 55,000 downloads) giving rise to a vast debate. The data have already been used in various published articles and analyses performed by other researchers, including the online genome community blogs that identified new models in the data that the authors had not previously appreciated. The results provided by this community have substantially improved the final version of the study.

References:

The formation of human populations in South and Central Asia - Vagheesh M. Narasimhan, Nick Patterson, Luca M. Olivieri, Alfredo Coppa et al. - Science 06 Sep 2019: Vol. 365, Issue 6457, eaat7487 DOI: 10.1126/science.aat7487