Scientist Works With Stem Cells During Days, Solves Jewish Genealogical Riddles At Night

"Most historians were skeptical. But the genetic evidence is one of the most surprising stories we've encountered."

Haredim pray near the tomb of Eleazar, the son of Aaron, in the West Bank. Photo credit: Menahem Kahana/AFP/Getty Images Files.

Scientist works with stem cells during day, solves Jewish genealogy riddles in spare time
Peter Goodspeed • National Post (Canada)

Dr. Karl Skorecki works on the cutting edge of molecular science, revolutionizing medicine through genetics and the use of stem cells to test anti-cancer therapies.

But as a sideline, the former University of Toronto professor has become world famous for applying genetics to genealogy and transforming history. He has found evidence to support traditional claims that modern-day Jewish priests, Cohanim, are descended from a single common male ancestor - biblically said to be Aaron, the older brother of Moses.

Among the other intriguing findings he has uncovered: that 40% of Ashkenazi Jews can trace their descent to four "founding mothers" who lived in Europe 1,000 years ago, evidence that all Jewish communities share a common paternal origin in the Near East, and genetic evidence supporting claims southern Africa's Lemba tribe may be Africa's "Black Jews."

"It began as a hobby, but it took on a life of its own," Dr. Skorecki says. "I didn't think anyone would really be that interested. I'm a nephrologist and a physician but I've always been interested in the genetic predisposition to disease."

Fifteen years ago, as he attended Shabbat services at his Toronto synagogue, Dr. Skorecki says his mind wandered during the reading of the Torah.

"A Cohen [Jewish priest] of North African, Sephardic, non-Ashkanazi origin was called up to read the Torah and it just got me to thinking what we have in common," he says.

"I myself am also a Cohen, but of recent European ancestry. It struck me as interesting that, on one hand, our paternal genealogies have been geographically separated for at least a thousand years. Yet, on the other hand, we share a Biblical oral tradition of common male ancestry dating back more than 100 generations."

According to tradition, the status of priest (Cohen) was conferred on Aaron and his sons, and has been passed on from father to son ever since the Exodus from Egypt.

As he sat in his Toronto synagogue, Dr. Skorecki says, "I realized if that were true, then it was a scientific hypothesis that was testable."

He reasoned the Cohanim should all have a common set of genetic markers at a higher frequency than the general Jewish population. After consulting Dr. Michael Hammer, a geneticist at the University of Arizona and a pioneer in studying the Y chromosome, the two men developed an experiment to test his thesis.

Besides determining maleness, the Y chromosome consists almost entirely of non-coding DNA, which is passed from father to son without recombination. Therefore the genetic information on a Y chromosome of a man living today is basically the same as that of his ancient male ancestors, with rare mutations that occur along hereditary lines.

By tracking those neutral mutations or genetic markers scientists can come up with the genetic signature of a man's male ancestry.

Dr. Skorecki's test found an array of six common chromosomal markers in 97 of the 106 Cohens he tested. Calculations based on variations of the mutations rooted the men's shared ancestry 106 generations in the past - 3,300 years ago, or the approximate time of Exodus.

He also discovered the common set of genetic markers in both Ashkenazi (European) and Sephardic (North African) Cohens, indicating they shared the same ancestry before their communities were separated more than 1,000 years ago.

"It's amazing," Dr. Skorecki says. "It's like an archeological finding. But instead of digging up in the sand, we dig in contemporary DNA."

His findings triggered a storm of interest in Jewish genealogy and the application of DNA analysis to the study of history.

The only child of Holocaust survivors, Dr. Skorecki was born and raised in Toronto. He took his medical degree at the University of Toronto, where he taught for 11 years before moving to Israel in 1995.

He is now director of the Rappaport Family Institute for Research in Medical Sciences and a researcher at the Rambam-Technion University Medical Center in Haifa, Israel's largest medical centre. After moving to Israel, Dr. Skorecki continued to dabble in genetic genealogy and conducted studies that suggest there is genetic evidence to support a common paternal origin for all Jewish communities.

In yet another study, Dr. Skorecki discovered an unusual genetic signature, thought to have originated in Central Asia, in more than half the Levites of Ashkenazi descent.

"They seem to be the descendants of one man who lived about 1,000 years ago somewhere between the Caspian and the Black Sea," he says. "Whether his ancestors originated there or he migrated from the Near East is unclear. We can't tell. But that is also the time and location of the mythical Khazar kingdom."

Dr. Skorecki says one of the most surprising discoveries of his genetic analysis of Jewish genealogy involves claims by the Lemba tribe of southern Africa to have Jewish origins.

The Bantu-speaking tribe of roughly 70,000, now mostly Christians, are spread across South Africa, Mozambique, Malawi and Zimbabwe. But the tribe's oral history claims Jewish ancestry, saying their founding fathers were Jews, led by a man named "Buba" who sailed to East Africa.

Unlike any of their surrounding neighbours, the Lemba observe many Jewish traditions, such as kosher-like dietary restrictions and slaughter practices, male circumcision and one holy day a week.

"Most historians were skeptical," Dr. Skorecki says. "But the genetic evidence is one of the most surprising stories we've encountered."

It is not clear whether the genetic origin was Jewish or Arab or a mixture. But a strikingly high number of Lemba males also carry the same genetic signature markers Dr. Skorecki discovered in modern-day Jewish Cohanim.

More remains to be done, but Dr. Skorecki is convinced genetic research is a powerful tool for historical study.

"It's not perfect. It's not physics. But it is not less reliable than lets say fossil records, archaeology, liturgy or oral histories," he says.

"In the larger context it adds further insight."

Comments

[maven]

"But it is not less reliable than lets say fossil records, archaeology, liturgy or oral histories" or fairy tales, myths, and other partial semi-histories.

After all, according to this, one needs to "explain" that a true Kohen was the individual who arrived in Central Asia, rather than the more likely explanation. I suspect the same truth that the Lemba story suggests, is that these genes are widespread in the local population, so that if one would change the denominator there would be no story here.

[soso]

I fear that this is an example of circular logic:

You look for common markers in 106 people, you find 6 markers that are common to 97 of them.

I suppose there are millions of markers. So it does not sound very convincing that this should be statistically relevent.

Besides, (in an earlier theory, perhaps with fewer markers) they did not have a very good "success rate".

What do you think?

[Shmarya]

All their work is published in peer reviewed scientific journals dealing with genetics.

[alternative childcare]

Shmarya: And that means what exactly?

[soso]

What they say in the peer reviewd scientific journals is not exactely the same as what is repeated in the rest of the media.

General Public press tends to over-emphasise the places where "it works" and under-emphasise (or leave out) the findings that do not fit in so well...

[Nachum]

He leaves out the less comfortable facts discovered, about, for example, Ethiopian Jews, matrilineal descent, and Leviim.

[maven]

Nachum, I would say "claims" rather than facts. Essentially in the past he has published that North African and Sephardic Jews map to local genes, which is no surprise to anyone other than racists and those who have ahistorical idealizations about Jewish identity.

[C-G]

What soso said is interesting, because even peer-reviewed articles sometimes make grandiose claims. This Skelecki paper that asserts a common Cohen lineage which split off into 6 distinct groups does that to some extent.

It's a very nice paper. But this jumped out at me: The length of time between submission of the original manuscript and its publication was four months. There is no mention of any revision of the original paper, but if a journal holds on to it for that long, it usually means that the editors or the reviewers had issues with the methods and/or data and/or conclusions. I know these things :-)

Even once a paper is published, it's not necessarily flawless. Other researchers will read it with a skeptical eye, looking out for inconsistencies and overblown claims. Here are a few things that troubled me:

Only 50% of the self-identified Cohanim in this study carry the Cohen Modal Haplotype (CMH)- which is the basis for the claim of common ancestry. That means that 50% don't. Of the 50% that do, less than 80% carry one of the 5 sub-haplotypes that the study honed in on as being the primary lineages that branched off of The One. This makes for an interesting study, but not one to bet your faith on.

Furthermore, the ages that were calculated for the branching off events are virtually the same, if you consider the ginormous standard deviations- a caveat that the authors admit. It seems odd that several haplogroups would sprung up at the same time and persisted, unchanged until the present.

The authors are honest and forthright about other theories which would also explain their results involving multiple original (unrelated) Cohanim predecessors (not just one). They play down one of two theories they present, but their means of reaching that conclusion is based on one algorithm, of which there are many. If someone else's lab crunched the numbers, they might get a more (or possibly less) convincing answer.

Then, seemingly contrary to their original claims, the authors mention that mutation alone would not account for these different haplogroups (wait--mutations are the basis for variation in haplotypes)...

...because the calculated ages of the genetic differences in Israel samples carrying these markers are "19.0 ± 5.6, 22.6 ± 2.9, and 15.1 ± 3.1 kyears, respectively" (a kyear is 1,000 years), which "predate[s] the foundation of the Jewish people". Hmmm.

The paper's conclusion backs away from the grandiose claims of elucidating biblical genealogy and includes this line:

"However, the sharing of several less frequent haplogroups (and modal haplotypes within these haplogroups) between Ashkenazi and non-Ashkenazi communities, as well as evidence for the persistence of population-specific Cohanim haplogroups, supports the formulation that males from other remote lineages also contributed to the Jewish priesthood, both before and after the separation of Jewish populations in the Diaspora."

...which is probably as close to the truth as anything.

The purpose of this comment is not to establish my credibility as a heretic, but to point out that this research, while interesting, should not be taken as scientific proof of the historical accuracy of the Torah.

If you'd like to see the paper, it's available here:

http://www.springerlink.com/content/357176p177623m41/fulltext.html

This group also published an article called "Multiple origins of Ashkenazi Levites: Y chromosome evidence for both Near Eastern and European ancestries" that suggests a common European (read: probably non-FFB) male ancestor from whom approx. 50% of Ashkenazi Levi'im are descended.

[C-G]

Correction-

"time between submission of the original manuscript and its acceptance was four months."

[R]

will they be using this technology to find out who amalek is?

[levi]

"He has found evidence to support traditional claims that modern-day Jewish priests, Cohanim, are descended from a single common male ancestor - biblically said to be Aaron, the older brother of Moses"

this is a gross misrepresentation of the actual findings bordering on fabrication

The original bearer of the CMH mutation is also the patriarch of many Magyars, Uzbeks and countless other ethnic groups. The rate of occurrence among self-proclaimed cohanim would only indicate that rate of common patrilineal descent from the original bearer of the mutation, who lived thousands of years earlier than the semi-mythical "aron"

[Uzi M]

"He leaves out the less comfortable facts discovered, about, for example, Ethiopian Jews"
Thats right. It now seems the whole Ethiopian Aliya was one big scam. Recent DNA studies show almost no similarities between ethiopian jews and other jewish people.

[nobody]

A Khazar kingdom really existed in history (albeit for a relatively brief time), so it is incorrect to call it "mythical." This kingdom actually stopped the advance of Islam and was situated right between the extensions of the Christian and Muslim empires at that time when it became Jewish.

[nobody]

"All their work is published in peer reviewed scientific journals dealing with genetics."

Shmarya fails to completely understand or properly characterize science or how it works, reflecting his lack of background in the subject. One should not relate to science in a fairytale manner.

In science, in all fields within science, there are good studies, and there are bad studies. BOTH types of studies get published in scientific journals through peer review. It is the responsibility of the trained reader of such studies to determine which category a given study falls into (good or bad). And this can be done based on certain fundamental parameters, none of which consist of "the peer editors at that journal are really good." (nor does it consist of saying "science is bunk" like an ignorant fundamentalist might claim).

There are studies with very convincing results, and there are studies with less convincing or even misleading claims (determined based on the analysis of their methods/results and validity or lack thereof). It is up to the responsible reader to discern between these different scenarios, not to say "all science is peer reviewed, and this is peer reviewed, therefore I know it's true."

[nobody]

Of course the reviewers do not intend to publish a bad study or let any such work get through the editorial stage. Alas, peer reviewers are only human, and they are fallible, and thus sometimes the bad studies do get published. Even more often, less or "only-slightly" convincing work gets published, and claims can often be overblown. Let's be rational.

[Guillermo DaGoy]

My father is a retired biologist(marine) and did similar studies in icthyology and herpatology. But fish can't build concentration camps.

[R]

Uzi M. Even you should know that one's jewishness isn't through the father, it's through the mother. What "house" you belong to is through the father.
You cannot use this sort of study to prove alot of things as it contains too many holes to be considered as solid.
But, it is interesting how far one go with DNA profiles and maybe it will help with other findings.

[R]

Read that as "how far one can go"

[cell functions]

the stem cell therapy will help us a lot!

[Genealogy Research]

That photograph is haunting. I can't imagine what it must be like living in that area of the world.

[Shmuel Ingalut]

I find it interesting that nobody I know is aware that the lineage of Cohen's was corrupted sometime after Pinchas, and remained so until the inauguration of the first Temple, at which time King Solomon returned the title to the lineage of Pinchas. We all know about Eli HaCohen and his sons. They were not Cohens. They were descended from the brother of Pinchas, not the son of Pinchas. And they lost the Ark of the Covenant because they were not endowed with the ability to use it. ( It was later returned by the Philistines). So, it's understandable, and well within reason to expect that only about half of those who believe they are Cohens are in fact genetic endowed as Cohens.