About 20 years ago a child of Holocaust survivors started wondering if studies of DNA could shed light on the Kohanic lineage. He is Dr. Karl Skorecki. He had graduated from medical swchool at the top of his class, and had gone through additional education and training (both clinical and research) at Harvard Medical School.
Dr. Skorecki’s question was simple. If there is a single male ancestor for a group of men alive today, might there be a genetic marker, or set of markers that are unique to that group of men on their male (Y) chromosome?
His original study was published in 1997 in the prestigious journal “Nature” and several subsequent studies have been published. His findings have been widely publicized. In religious communities then work has been publicized as proof of the Kohane lineage. In non-religious communities the work has been derided as proof that there is no kohanic lineage. Both extreme depictions of the work are wrong.
The Skorecki and subsequent studies do not claim to demonstrate specific and definitive Kohane genetic markers. Nonetheless the findings are interesting. I believe that they support the traditional knowledge that many of today’s Kohanim have common male ancestry.
The initial study looked at a pair of markers on the Y (male ) chromosome. Subsequent studies have looked at more markers.
In brief overview the studies have found that:
- These markers occur together in a very small percentage of the world’s male population (well under 1%).
- Among Jews the markers appear in combination in meaningful percentages (somewhere around 10%).
- Among men identified as Kohanes, the markers appear in much higher percentages (somewhere around 50%).
- The percentatges vary a little in different Jewish communities – but the numbers among the Kohanes are always higher than among the non-Kohanes.
While these numbers clearly do not prove whether specific people are direct descendants of Aaron, it is also clear that there is an ancestral commonality that cannot be coincidental.
Is it possible that researchers like Dr. Skorecki might someday find a definitive “Kohane gene?” Not likely. Studies of genetic trends depend on incessant small changes in DNA from generation to generation. Every time a new cell is formed the DNA for that cell is replicated from a predecessor, and in the replication process a chain reaction is triggered that causes the production of proteins and other biochemical derivatives. The process is complex, a bit messy, and imperfect, and is happening in every cell of every person. After 3,300 hundred years it is not likely that a reliable kohane gene can be found.
But the statistical evidence found by Dr. Skorecki and his colleagues is far from mere coincidence.