30 January 2025 The Future is the Product of the Past

Scientists have developed a new tool that enables them to identify prehistoric and historic individuals’ relatives up to the sixth-degree

A new method of genetic analysis makes it possible to determine family relationships of prehistoric and historical individuals up to the sixth degree. Methods used so far only managed this up to the third degree. This innovation will help scientists identify previously unknown connections between people and cultures of the past.

Scientists from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and the University of Harvard in the United States have developed a new tool that allows them to identify the relatives of prehistoric and historic individuals up to the sixth degree.

If two persons are biologically related, they share long stretches of DNA that they co-inherited from their recent common ancestor. These almost identically shared stretches of genomes are called IBD (“Identity by Descent”) segments. Up to the sixth-degree relatives – such as second to third cousins would be, or a great great great great grandparent – the two relatives even share multiple IBD segments. Personal genomics companies such as 23andme or Ancestry detect those segments routinely in DNA of their customers, and use this signal to distinctively reveal biological relatives in their databases.

In a new study, researchers have now developed a powerful new tool named “ancIBD”  to extract these IBD segments also in genomes of humans who lived hundreds, thousands, or even tens of thousands of years in the past. The critical challenge was that such ancient genomes are often very degraded and therefore of much worse quality than modern DNA, so the authors had to come up with an innovative trick to fill in gaps in ancient genomes using modern reference DNA panels.

This advance unlocked completely new ways to analyze ancient DNA data. “By precisely measuring the regions of shared genome we can now detect pairs of up to sixth-degree relatives also in ancient genomes, while previous aDNA methods using genomic average similarities were limited to detecting only up to third-degree relatives,“ explains Yilei Huang, a first author of the study and PhD researcher at the Max Planck Institute for Evolutionary Anthropology.

The figure shows shared IBD segments (shown in blue with their location on the 22 human chromosomes) between pairs of relatives. Using their new method, the authors were able to detect these stretches of identical DNA in four people from Neolithic England who lived about 5,700 years ago and are buried in the Hazleton North Long Cairn. Up to the sixth degree of relationship, people usually share several long IBD segments – the new tool can now determine these precisely. Fig. © Ringbauer & Huang et al., Nature Genetics (2023)

Researchers identified hundreds of new pairs of relatives

The authors then applied their new tool to a dataset of 4,248 previously published ancient genomes from across Eurasia and the last 50,000 years and were able to identify hundreds of previously undetected pairs of relatives. In some fascinating cases, the two relatives were buried a large distance apart, which directly revealed the mobility of past people. In one such case, the authors detected a pair of two Early Bronze Age nomads from Central Asia who lived ca. 5,000 years ago and were fifth-degree relatives who were buried ca. 1,500 kilometers apart from each other. These individuals, or their immediate ancestors, must have moved hundreds of kilometers between being born and being buried.

The new tool allowed the authors to also investigate even more distant relatives with unprecedented precision. Not all such relatives beyond the tenth degree share long IBD, but the authors could measure the average rate of sharing long DNA between groups of ancient people. These signals revealed previously unknown connections. “We found exciting links between ancient cultures, and the signal of long shared segments allowed us for the first time to specifically demonstrate close relationships between important ancient cultures, sometimes over vast spaces over the order of only a few hundred years,” says Harald Ringbauer from the Max Planck Institute for Evolutionary Anthropology, the lead researcher of this study.

Gene flow from the Eurasian Steppes

Among other things, the authors revealed fascinating new details about a massive gene flow from the Eurasian steppe that began around 5,000 years ago. The first Europeans with substantial steppe ancestry, associated with Corded Pottery, an archaeological culture that then spread from Central Europe to Scandinavia and present-day Russia, share many long IBD segments with the Yamnaya herders of the Pontic-Caspian steppe. This suggests a distinct genetic bottleneck event and a biological connection between these groups of populations that dates back only a few hundred years.

The authors also found elevated sharing of long IBD segments between Corded Ware individuals and East European people associated with the Globular Amphora culture (GAC) from Poland and Ukraine, who were not yet carrying Steppe-like ancestry. “These IBD links appear for all Corded Ware groups across Central Europe to Russia, indicating that individuals related to GAC contexts must have had a major demographic impact early on in the genetic admixtures giving rise to various Corded Ware groups,” says Ringbauer.

The new method to screen ancient DNA for parental relatedness gives researchers a versatile new computational tool. Looking forward, the field of ancient DNA is quickly developing, with thousands of ancient genomes being produced every year. By revealing close and distant biological relatives, the new tool will allow researchers to shed new light on the lives of our ancestors, both on the small scale, relevant to understanding the life stories of people and their relatives, and on the macroscale, relevant to large-scale cultural-historical events.

Max Planck Institute for Evolutionary Anthropology

DOI: 10.1038/s41588-023-01582-w 

Cover image: © Ringbauer & Huang et al., Nature Genetics

Related Articles

Roman soldier’s 1,900-year-old payslip uncovered in Masada

16 February 2023

16 February 2023

During excavations at Masada, archaeologists from the Israel Antiquities (IAA) uncovered a papyrus payslip dated to 72 BC belonging to...

Archaeologists unearth mosaic floors in the ruins of a building they believe is the lost Church of the Apostles

23 October 2021

23 October 2021

In the historical village of Bethsaida on the edge of the Sea of Galilee, archaeologists discovered mosaic floors in the...

Fragments of ‘unique’ 17th-century iconostasis discovered in Polish church

28 October 2023

28 October 2023

Researchers from the Institute of Art at the Polish Academy of Sciences (IS PAN) have discovered substantial fragments of a...

Archaeologists Uncovered a Roman-Era Clay Theater Ticket in Ancient City of Prusias ad Hypium

1 December 2024

1 December 2024

Excavations at the ancient city of Prusias Ad Hypium in the Konuralp region of Düzce in northwestern Türkiye have uncovered...

“Mosaic of the Wine Harvest” mosaic to be exhibited in November in Turkey’s Hatay

26 October 2021

26 October 2021

The mosaic depicting the grape harvest, which is considered to date from the Late Roman period, equivalent to the 5th...

The mystery of the silver bracelets of Queen Hetepheres in her celebrated tomb at Giza solved

2 June 2023

2 June 2023

The discovery of silver bracelets in the tomb of Queen Hetepheres I, wife of Pharaoh Snofru and mother of Pharaoh...

The Oldest Odin Inscription in the World Found in the Vindelev treasure

8 March 2023

8 March 2023

Scientists have identified the earliest known inscription referring to the Norse god Odin on part of a gold disc unearthed...

Comb and gold hair-ring dating back more than 3,000 years unearthed in south Wales

14 July 2023

14 July 2023

Archeologists in south Wales, have unearthed a golden hair ring and the oldest wooden comb ever found in the U.K....

Oldest known alphabet unearthed in ancient Syrian city -500 years older than thought

22 November 2024

22 November 2024

Johns Hopkins University researchers uncovered evidence of the oldest alphabetic writing in human history. The writing was etched onto finger-length...

‘Roman numerals’ discovered on Stone of Destiny ahead of King Charles III coronation

8 April 2023

8 April 2023

New research has revealed previously unrecorded markings that appear to be Roman numerals on the Stone of Destiny, considered one...

Marmore, the Highest and Oldest Artificial Waterfall in Europe, Created by the Romans

4 March 2024

4 March 2024

Approximately eight kilometers away from the town of Terni in Umbria, Italy, there is a waterfall that is one of...

Ancient terracotta dancers, and musicians unearthed in China

13 November 2022

13 November 2022

Chinese archaeologists recently discovered a large group of terracotta figurines from a tomb in a group dating to the Northern...

1900 years old a Customs Inscription from the Lycian civilization reveals Anatolia’s strategic importance in maritime trade

16 September 2023

16 September 2023

A Customs Inscription from the Lycian civilization, located in Andriake port in the southern province of Antalya’s Demre district, tells...

Archaeologists unearth 6,000-year-old two monumental mounds containing wooden grave chambers in Germany

16 March 2024

16 March 2024

Archaeologists from the State Office for Heritage Management and Archaeology Saxony-Anhalt (LDA) have uncovered a significant Neolithic burial landscape on...

Farmer Found an Ice Age Cave Under His Field

30 March 2021

30 March 2021

A naturally formed cave was found near the town of Kraśnik in southeastern Poland, used by humans during the Ice...