NEW YORK (GenomeWeb) – A new ancient genome sequencing study suggests that the present-day population of Lebanon has genetic ties to the influential Canaanite population, which made its home in the Levant during the Bronze Age.
As reported today in the American Journal of Human Genetics, an international team led by investigators in the UK and Lebanon did whole-genome sequencing on a handful of 3,700-year-old samples from a Canaanite city state called Sidon. When analyzed alongside new and available genome sequences or genotyping profiles, the ancient sequences pointed to shared ancestry for the Canaanites and some individuals from Sardinia and Northern Italy, along with Canaanite ancestry in the modern Lebanese population.
"In light of the enormously complex history of this region in the last few millennia, it was quite surprising that over 90 percent of the genetic ancestry of present-day Lebanese was derived from the Canaanites," senior author Chris Tyler-Smith, a human evolution researcher and senior group leader at the Wellcome Trust Sanger Institute, said in a statement.
Historians have placed the Canaanites in the area that is now Israel, Palestine, Lebanon, Syria, and Jordan starting a few thousand years ago, the team noted, though there has been debate surrounding the group's origins and present-day relationships, if any.
"[T]he Bible reports the destruction of the Canaanite cities and the annihilation of its people; if true, the Canaanites could not have directly contributed genetically to present-day populations," Tyler-Smith and his co-authors noted. "However, no archaeological evidence has so far been found to support widespread destruction of Canaanite cities between the Bronze and Iron Ages: cities on the Levant coast such as Sidon and Tyre show continuity of occupation until the present day."
Using the Illumina HiSeq 2500 instrument, the researchers sequenced ancient DNA libraries generated with genetic material isolated from 3,650 to 3,750-year-old bone samples from five Canaanite individuals in Sidon, generating between 0.4- and 2.3-fold nuclear genome coverage and 53- to 164-fold mitochondrial genome coverage.
The team also generated roughly 8-fold genome coverage for 99 modern individuals from Lebanon. For its subsequent principal component analysis, the group folded in existing whole-genome sequence data for four Lebanese individuals sequenced to around 30-fold coverage, along with Lebanese genotyping profiles and available sequence data for individuals from several other populations.
The researchers' results point to present day populations — particularly in Lebanon — showing Canaanite ancestry, consistent with a degree of genetic continuity in the Levant. The Lebanese population also showed signs of Eurasian ancestry that was interjected roughly 2,170 to 3,750 years ago.
Based on their results, they suspect that the Canaanites themselves were descendants of Neolithic farming or pastoral nomad groups that mixed with more migratory populations from the east.
"We found that the Canaanites were a mixture of local people who settled in farming villages during the Neolithic period and eastern migrants who arrived in the region about 5,000 years ago," co-first author Marc Haber, a post-doctoral researcher with Tyler-Smith's Sanger Institute group, said in a statement. "The present-day Lebanese are likely to be direct descendants of the Canaanites, but they have in addition a small proportion of Eurasian ancestry that may have arrived via conquests by distant populations such as the Assyrians, Persians, or Macedonians."
Tyler-Smith, Haber, and their co-authors cautioned that "[m]any of our inferences rely on the limited number of ancient samples available, and we are only just beginning to reconstruct the genetic history of the Levant or the Near East as thoroughly as that of Europeans who, in comparison, have been extensively sampled."