Thousands of years ago in what is now northern Israel, waves of migrating people from the north and east - present-day Iran and Turkey - arrived in the region. And this influx of newcomers had a profound effect, transforming the emerging culture. What's more, these immigrants introduced new genes - such as the mutation that produces blue eyes - that were previously unknown in that geographic area, according to a new study.
     Archaeologists recently discovered this historic population shift by analyzing DNA from skeletons preserved in an Israeli cave. The site, in the north of the country, contains dozens of burials and more than 600 bodies dating to approximately 6,500 years ago, the scientists reported. DNA analysis showed that skeletons preserved in the cave were genetically distinct from people who historically lived in that region. And some of the genetic differences matched those of people who lived in neighboring Anatolia and the Zagros Mountains, which are now part of Turkey and Iran, the study found.
     Ancient Israel experienced a significant cultural shift during the Late Chalcolithic period, around 4500 to 3800 BCE, with denser settlements, more rituals performed in public and a growing use of ossuaries in funerary preparations, the researchers reported.
     The authors of the new study suspected that waves of human migration explained the changes. To find answers, the scientists turned to a burial site in Israel's Peqi'in Cave.
     Measuring around 56 feet (17 m) long and about 16 to 26 feet (5 to 8 m) wide, the cave contained decorated jars and burial offerings - along with hundreds of skeletons - suggesting that the location served as a type of mortuary for Chalcolithic people who lived nearby. However, not all of the cave's contents appeared to have local origins, study co-author Dina Shalem, an archaeologist with the Institute for Galilean Archaeology at Kinneret College in Israel, said in a statement.
     The scientists sampled DNA from bone powder from 48 skeletal remains and were able to reconstruct genomes for 22 individuals found in the cave. The scientists found that these individuals shared genetic features with people from the north, and those similar genes were absent in farmers who lived in the region earlier.
     The scientists also discovered that genetic diversity increased within groups over time, while genetic differences between groups decreased; this is a pattern that typically emerges in populations after a period of human migration, according to the researchers. "The publication of the artifacts from Peqi'in has shown many cultural links between these regions, but it will be interesting to see, in the future, whether those links are genetic as well," said Daniel Master, a professor of archaeology at Wheaton College in Illinois.

Edited from LiveScience (24 August 2018)