http://www.terra.net.lb/wp/Articles/...41&ChannelId=5Gene study charts arrival of Islam, Crusaders in Lebanon
March 31, 2008
A new study has found genetic traces of both the arrival of the Crusades and of the expansion of Islam in Lebanon, as reported by the National Geographic Magazine on Friday.
The findings not only confirm well-documented history but also present a rare genetic trail showing the movement of two major religions into Lebanon, scientists say.
"Lebanon has always had a rich history of receiving different cultures," said the study's lead author, Pierre Zalloua, an associate professor at the Lebanese American University. "This study tells us that some of them did not just conquer and leave behind castles. They left a subtle genetic connection as well."
Unlike previous studies that have relied on mitochondrial DNA - which is passed on maternally - to unlock secrets of human migration, researchers in the current study focused on the paternally provided Y chromosome, as it is thought to provide more detailed information.
The distribution of genetic markers at first appeared virtually indistinguishable across the Christian, Druze, and Muslim populations of Lebanon. But a closer look at the Y chromosomes of 926 Lebanese men sampled in the study revealed something intriguing.
"We noticed some interesting lineages in the dataset. Among Lebanese Christians, in particular, we found higher frequency of a genetic marker - R1b - that we see typically see only in Western Europe," said Spencer Wells, a National Geographic Explorer-in-Residence.
Wells said that the lineage was seen enriched to a higher frequency only in the Christian populations in Lebanon and was not seen in the Muslim section of the population.
"It certainly doesn't undermine the similarities among the various Lebanese communities, but it does agree with oral tradition - that some Lebanese Christians are descendents of Crusaders - and points to a genetic connection to the Crusaders," he added.
"We have a correspondence between what we knew about the history of the region from written documents and what we're starting to see that in the genetic patterns as well."
"Now what historical events would have brought a substantial number - 2 percent - of Y chromosomes in the Christian population in from Western Europe?" he added. "The most likely answer is the Crusades."
The National Geographic researchers say that their discoveries suggest, in particular, that Crusaders from the 11th to 13th centuries A.D. introduced their lineages into the existent Lebanese population.
The genetic researchers also noticed a similar pattern when they looked at Y-chromosome lineages in the Muslim parts of the population.
The expansion of Islam from the Arabian Peninsula beginning in the seventh century A.D. likely introduced lineages into people who subsequently became Lebanese Muslims, they add. - The Daily Star
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Full study with all the graphs...
http://www.ajhg.org/AJHG/fulltext/S0002-9297(08)00206-1 
Mon Nov 17, 2008 6:09 pm