A team of scientists has determined that settlers with blue eyes and fair skin inhabited the Levant — a historical geographical term referring to a large area in the Eastern Mediterranean — about 6,500 years ago. The researchers used a dedicated cleanroom facility at Harvard Medical School to examine bone powder from skeletal remains to analyze ancient DNA.
The team mapped the genomes of bones taken from 22 of the 600 individual skeletons discovered in a massive necropolis near Peki’in, in the northern part of modern-day Israel. The Peki’in burial cave is the biggest burial site ever identified from the Late Chalcolithic period (aka the Copper Age) in the area. The site was discovered by accident in 1995, when a tractor performing roadwork caused a portion of the cave’s roof to collapse.
Upon examination of the DNA, the scientists found that the ancient people had a genetic mix not like that of other settlers of the region. The Peki’in people instead shared “substantial” ancestry with people who lived further north, in modern-day Iran and Turkey.
The Peki’in genome mapping now fills a gap of about 3,000 years in DNA analysis of regional peoples — last year, an article was published saying that Bronze Age burial research shows 93 percent of the ancestry of modern Lebanese ancestry comes from the Canaan area, in the southern Levant.
The research is important because it shows a pattern of migration; some have suggested that artifacts (which had origins in Turkey and Iran) that had been found in ancient burial sites were merely the result of trade.
The Peki’in burial site is also thought by scholars to be a place of great importance and reverence, as there is evidence that some of the bodies found within had originated in the Jordan Valley, the Judean and Negev deserts, and the coast of Lebanon. Radiocarbon dating has shown that the cave was in use during the period of 4500-3900 BCE. The site was also rampant with grave robbers during ancient times, and they likely took many of the metal objects that are thought to have been left with the dead.
Those working in the Harvard cleanroom facility extracted bone powder from 48 skeletal remains, “of which 37 were petrous bones known for excellent DNA preservation,” according to the article in Nature Communications. The team extracted the DNA to construct next-generation sequencing libraries with unique bar codes attached, in order to minimize the chance of contamination. The libraries were treated with Uracil-DNA glycosylase (UDG) to reduce characteristic ancient DNA damage at all but the first and last nucleotides.
The data was obtained from 22 individuals, and the researchers say that the quality is exceptional especially considering that it is difficult to find well-preserved DNA in the warm climate of the Middle East. Genetic analysis suggests that 20 of these individuals were not related to each other in the first, second, or third degree.
The DNA results reveal how migrants from other areas influenced the population within the southern Levant region, giving a fascinating look at how society grew and changed over time.