Tag Archives: Genetics

The Origins of Ashkenazi Jews

In this week’s parasha, Noach, we read about how the seventy primary descendants of Noah settled the Earth after the Great Flood. Noah had three sons, and it is often said that they divided the three continents of the Old World amongst them: Yefet (Japheth) got Europe, Shem got Asia, and Ham got Africa. This is not exactly accurate.

For one, Canaan is a son of Ham, but did not inhabit Africa, while Nimrod is said to be a son of Cush—also of Ham—yet we know Nimrod ruled Mesopotamia (Genesis 10:10). Another son of Ham is Mitzrayim, which is Egypt, yet Mitzrayim’s own children include Pathrusim and Caphtorim, names generally associated with Greek lands. (There is historical evidence to suggest that the early pre-Greek peoples did come from Egypt.) Yavan, the classic term for Greece, is a son of Yefet. As discussed in the past, Yavan is the same as Ionia, which is the western coast of Turkey, then inhabited by Greek-speaking peoples. (The famous city of Troy was in Ionia, in modern-day Turkey.)

In fact, essentially all of the seventy places inhabited by Noah’s descendants are places in modern Turkey or the Middle East. This makes sense, since the Torah was originally speaking to an audience that was unaware of most of Europe, the Far East, sub-Saharan Africa, and needless to say, the New World. The Torah mentions the origins of those territories that were familiar to the ancient Israelites, and that would have been their immediate neighbours. It also makes sense practically, since Noah got off the Ark in Ararat—somewhere in modern Turkey—and his children and grand-children would have settled lands that weren’t too far away from there.

Mt. Ararat, as seen from Yerevan, Armenia. It isn’t certain whether this Ararat is the Biblical Ararat.

One of Noah’s descendants is named Ashkenaz (Genesis 10:3). He is a grandson of Yefet, whose children all seem to have inhabited territories in Asia Minor and Armenia. Ashkenaz, too, is in that vicinity. Even in the time of the prophet Jeremiah centuries later, Ashkenaz was a kingdom in Turkey: “Raise a banner in the land, blow the shofar among the nations, prepare the nations against her, call together against her the kingdoms of Ararat, Minni, and Ashkenaz…” (Jeremiah 51:27) The prophet goes on to call on these and other powers in the area to come upon Babylon. Ashkenaz is one of the Turkish kingdoms bordering Babylon to the north, along with Ararat.

Modern-day villages in Northeastern Turkey. (Credit: theconversation.com)

Amazingly, to this day ethnic Armenians in the region name Ashkenaz as one of their ancestors! This claim is not recent; the fifth-century Armenian scholar Koryun described the Armenians as an Askanazian people. Not surprisingly then, multiple places in Northeastern Turkey today still bear similar-sounding names, including the villages of Iskenaz, Eskenez, and Ashanas.

If Ashkenaz is a place in Turkey, how did it become associated with European Jews? Did Ashkenazi Jews come from Turkey?

Debunking Khazaria

One popular explanation for the Turkey-Ashkenaz connection points to the Kingdom of Khazaria. This was a wealthy and powerful kingdom that ruled the Caucasus, southern Russia, and parts of Turkey and Eastern Europe in the Middle Ages. Historians credit the Khazars with checking the rapid Arab conquest, and preventing a Muslim takeover of Europe from the East. It is said that around 740 CE, King Bulan grew tired of his people’s backwards pagan beliefs and converted to Judaism. According to legend, he had invited representatives of the major faiths to argue their case, and concluded that Judaism was the true faith. (This is the basis of Rabbi Yehuda haLevi’s [c. 1075-1141] famous text, the Kuzari.)

Although Bulan did not impose his new religion on anyone, it is thought that much of his kingdom had become Jewish anyway within about a century. Remarkably, a large reserve of antique Khazar coins was found in Sweden in 1999, bearing the inscription “Moses is the Prophet of God”. (Modeled on, and sometimes just refashioned from, Arab coins saying that “Muhammad is the Prophet of Allah”!) Archaeologists have found similar Khazar coins all over the Old World, from England to China, showing the tremendous extent of Khazaria’s wealth and influence.

Khazar coin from c. 837 CE, with the inscription “Moses is the prophet of God”.

Like all kingdoms, Khazaria had an expiration date. It was eventually overrun by the Rus, Mongols, and others. Some say that many Jewish Khazar refugees migrated westward to Europe, and settled in the sparsely populated and resource-rich lands of Germany. Since they had come from a place traditionally known as Ashkenaz, they were labelled “Ashkenazi Jews”. This is a great story, but one that has far too many holes.

From a historical perspective, most scholars reject the Khazar hypothesis simply because there is little evidence that Khazaria experienced a mass conversion to Judaism. It is generally agreed that only a small portion of the Khazar nobility had converted, at best. Khazaria simply attracted many Jews to settle there since it was a rich kingdom with freedom of religion. In that case, any Jewish refugees that might later flee Khazaria to Europe would not be ethnic Khazars anyway.

The Schechter Letter

Then came a huge discovery from the Cairo Geniza. Now known as the Schechter Letter (as it was discovered by Solomon Schechter, 1847-1915), the text is a correspondence between a Khazari Jew and a Sephardi Jew, most likely Hasdai ibn Shaprut (c. 915-970 CE). The letter includes a brief history of Khazaria, and states that Khazaria’s Jews originally came from Persia and Armenia, from which they had fled persecution. One of their descendants, named Sabriel, eventually rose to Khazarian nobility, and finally became king. His wife, Serach, convinced him to go public with their Jewish heritage, and they did, inspiring others in the kingdom to convert to their new king’s religion.

The Schechter Letter confirms that the majority of the Jews in Khazaria were not actually Turkic converts but migrants from Persia and Armenia. Shortly after the letter was written, the Khazari Kingdom fell apart in 969 CE. (We know the letter must have been written after 941 CE, since it refers to a battle in that year for which we have other historical records.) The supposed Jewish exodus from Khazaria would have happened in the ensuing decades.

Yet, we read in the commentaries of French-born Rashi (Rabbi Shlomo Itzchaki, 1040-1135) how he learned certain things from his visits to Jewish communities in neighbouring Ashkenaz (see, for example, Ketubot 77a), and that Ashkenaz is undoubtedly German (with Rashi occasionally using German/“Ashkenazi” words, as in Sukkah 17a, for instance). This implies that by Rashi’s time—less than a century after the fall of Khazaria—a geographical region in Western Europe referred to as “Ashkenaz” was already well-known, with Jews there freely conversing in German. It is unlikely that this would happen so soon after the fall of Khazaria; Ashkenaz must have existed long before.

Besides, we know that Jews already lived in Europe at the time of Charlemagne (742-814 CE), who had a good relationship with his Jewish subjects. Charlemagne was born right around the time King Bulan is supposed to have converted to Judaism, and before the rise of Sabriel (whom some identify with Bulan). This alone proves that Jews were already living in Europe long before any Khazari Jews appeared on the scene.

Among the Ashkenazi Jews of the Middle Ages themselves, the tradition was that they had been there since the destruction of the Second Temple. For example, the Rosh (Rabbi Asher ben Yechiel, c. 1250-1327) wrote in one of his response (20, 20) that when he moved to Toledo, Spain:

I would not eat according to [Sefardi] practice, adhering as I do to our own custom and to the tradition of our blessed forefathers, the sages of Ashkenaz, who received the Torah as an inheritance from their ancestors from the days of the destruction of the Temple. Likewise the tradition of our predecessors and teachers in France is superior…

A portrait identified with Rabbeinu Asher ben Yechiel, the “Rosh”

The Rosh speaks of three distinct European Jewish communities: Sefarad, Ashkenaz, and Tzarfat (France). This makes one wonder whether Rashi would have considered himself Ashkenazi (as people typically see him today) or Tzarfati? Rashi was born and died in Troyes, France, though he spent time in Worms and Mainz in Germany, hence the reference above to his having learned things while visiting “Ashkenaz”. This implies that Rashi may not have considered himself Ashkenazi at all. (His father was called Rabbi Itzchak haTzarfati, and though he lived for a time in Worms, probably hailed from Lunel in Southern France.) Whatever the case, we see that the Sefardi, Ashkenazi, and Tzarfati Jewish communities were already firmly entrenched at the time of Khazaria’s fall.

Delving into Ashkenazi Genes

Science can shed further light on Ashkenazi origins. One study of mitochondrial DNA (mtDNA, which is passed strictly from mother to child) found that some 40% of Ashkenazi Jews come from a group of mothers in Europe, possibly converts, approximately 2000 years ago (another related study here). This would have been around the destruction of the Second Temple. We know that many Jews fled Judea (or were expelled) at the time, and settled across the Roman Empire and beyond. Similarly, a study of Y chromosomes (passed strictly from father to son) shows that most Ashkenazi Levites have a common ancestor who lived at least 1500 years ago, most likely in the Middle East or already having migrated to Europe. These scientists conclude that the Khazar hypothesis is “highly unlikely”.

Other genetic studies do appear to show high degrees of relatedness between Turkic and Iranian peoples with Ashkenazi Jews, especially males. Of course, Jews have lived and migrated just about everywhere, and undoubtedly mixed with local populations, while drawing numerous converts. One interesting study found that about 5% of Ashkenazi males are part of the Q3 haplogroup, part of the wider Q group which represents Native Americans and Asians. The researchers concluded that Q3 entered the Jewish gene pool sometime in the 1st millennium. Some say this is due to the Ashina Turks (among the Khazar elite) who converted to Judaism and took Jewish wives. Either way, it is only a tiny minority of Ashkenazis that carry such genes.*

What we see from genetic studies is that most Ashkenazi Jews today descend from ancestors that were already in Europe long before the rise of the Khazars. Historical evidence confirms the existence of widespread Jewish communities in Europe before the time of Khazaria, too. In reality, the Khazar hypothesis keeps being resurrected because it is a convenient tool for anti-Semites to attack modern Jews as “imposters” (meanwhile completely forgetting the other half of the world’s Jews which are not Ashkenazi at all!) or for anti-Zionists to deny a Jewish connection to the land of Israel.

Having said all that, we must still answer the key question: where did the “Ashkenazi” label come from?

Adapting Names

When we look at the seventy “original” nations—descendants of Noah—we find that they represent a very small geographical area. Of the seventy, fourteen come from Yefet and represent Asia Minor, Armenia, and the Aegean islands (Genesis 10:5), nine are Cushites (presumably dark-skinned people), eight of Mitzrayim, twelve are Canaanites, and twenty-six are Middle Eastern, or possibly even just Mesopotamian. As already mentioned, the Torah’s narratives are confined to a narrow geographical space that was relevant to the ancient Israelites.

A “Table of Nations” from the ArtScroll Stone Chumash

When Jews started migrating out of Israel and beyond the Middle East, they needed to come up with names for these new territories they inhabited. So, they adapted the Biblical place-names of locations that no longer existed or whose identity was no longer known. For example, Sefarad became Spain and Tzarfat became France. When scripture speaks of Sefarad or Tzarfat (as in Ovadiah 1:20), it is certainly not speaking of Spain or France! For instance, the prophet Elijah went to Tzarfat, which is described as being next to Sidon (I Kings 17:9). Sidon is, of course, a well-known ancient city, in what is now Lebanon.

For the first Jews who settled in Spain and France, they had migrated the farthest West they could possibly go at the time. For them, these new lands were the most distant from Jerusalem, so they fittingly adapted terms for places described as being exceedingly far from the Holy Land (as in Ovadiah 1:20). They couldn’t use the names of places that were still extant, but only those ancient names that were no longer relevant. In the same fashion they described Germany as “Ashkenaz”, while Bohemia was surprisingly called “Canaan”. Therefore, to say that Ashkenazi Jews are Turkish because Ashkenaz was originally a place in Turkey is like saying French Tzarfati Jews are Lebanese because Tzarfat was originally a place in Lebanon!

It is worth pointing out here that scholars have also recently pinpointed the Biblical Sefarad. There is now strong historical evidence to identify Sefarad with the ancient town of Sardis, also in Asia Minor (modern Turkey), of course. Sardis was known to the Lydians who inhabited it as Sfard, and to the Persians as Saparda. It goes without saying that Sephardic Jewish origins have nothing to do with Turks, as don’t the origins of Lydians (probably the “Ludim” of Genesis 10:13, or the Lud of Genesis 10:22), nor the Yavanim, the Greek Ionians, all of whom inhabited that same area of Asia Minor.

The Tower of Babel

‘Turris Babel’ by Athanasius Kircher (1602-1680)

After telling us the divisions of the nations in Genesis 10, the Torah goes on to relate the narrative of Migdal Bavel. We are told that the people were all still unified at this point, speaking one tongue. They gathered in Babylon to build a tower to the Heavens, with nefarious intentions. Their plans were thwarted by God, who then scattered the people all over the world and confounded their tongues.

From a mystical perspective, at this point those seventy root nations—which originally inhabited Asia Minor and the Middle East—were spread all around the globe into a multitude of various peoples with new cultures and languages. Thus, all of the world’s thousands of nations and ethnicities, wherever they may be, are spiritually rooted in one of Noah’s seventy descendants.

Consequently, there were those who believed that Ashkenaz was dispersed to Central Europe. What’s amazing is that this was not only a Jewish belief, but a Christian one, too. The evangelical Christian pastor Ray Stedman (1917-1992) wrote:

The oldest son of Gomer was Ashkenaz. He and his descendants first settled around the Black Sea and then moved north into a land which is called Ascenia, and which later became known as the Islands of Scandia, which we now know as Scandinavia. You can trace a direct link between Ashkenaz and Scandinavia.

Basing himself on earlier sources, he lists Ashkenaz as referring to all Saxons, Scandinavians, and Germanic tribes. This argument was made at least as far back as the 4th century (long before the Khazars appeared on the scene), in Eusebius’ Historia Eccliesiastica, where Ashkenaz is Scanzia, another name for Scandinavia and/or Saxony.

Around that same time, the Talmud (Yoma 10a) identifies Gomer (the father of Ashkenaz) with Germamia. While this Germamia is possibly referring to Cimmeria, or Germanikia in Syria—which would have been more familiar to the Babylonian Sages living in the Persian Empire—it is very likely that Jews who settled in Germany would see Germamia as referring to their new land. Combined with the alliteration between “Ashkenaz” and “Saxony”/“Scanzia”, we can understand why the Jews that settled in Germany adapted the name Ashkenaz.

As an intriguing aside, the Talmud cited above holds that Yefet is a forefather of the Persians, too. The Talmud reads: “How do we know that the Persians are derived from Yefet? Because it is written: ‘The sons of Yefet: Gomer, and Magog…’” The Sages seem to connect Magog with the Persians. That might make alarm bells go off in the heads of modern readers who see Iran as playing a central role in an End of Days Gog u’Magog scenario.

To conclude, the hypothesis that Ashkenazi Jews originate among Turkish converts is completely false. While some Turkish converts certainly joined the Jewish nation in the Middle Ages, Ashkenazi Judaism predates this phenomenon by centuries. Both historical evidence and genetic analyses confirm a European Jewish presence as far back as 2000 years ago.


*Shortly after publishing this article, Kevin Brook pointed out the following to me, from his book The Jews of Khazaria (pg. 204):

Some researchers thought it was possible that these could have been inherited from the Khazars, but this idea is no longer viable. Ashkenazim belong to the Q haplogroups that were later precisely identified as Q-Y2200 (Q1b1a1a1a) and Q-YP1035 (Q1b1a1a1a2a2). On the Y chromosome tree, Q-Y2200’s parent haplogroup Q-Y2225 (Q1b1a1a1) was found in an Italian sample from Sicily, and geneticists determined that QY2225’s distant ancestors had apparently lived in the Middle East. The Ashkenazic branches of Q are very different from Q1a1b-M25 and Q1a2-M346, which are common among Turkic-speaking peoples, and the common ancestor between them all lived many thousands of years ago, far in advance of Khazaria’s existence.

Why is Judaism Matrilineal?

In this week’s parasha, Va’etchanan, God cautions His people about intermarriage (Deuteronomy 7:3-4). Although the Torah is speaking specifically about intermarrying with the Canaanite nations, the verses have always been understood as prohibiting intermarriage with any and all other nations. This is especially true because the Torah goes on to say that intermarrying will lead to the children being led astray and being turned to idolatrous ways. In those days, the Canaanites were not the only idolaters, of course—just about everyone was an idol-worshipper—so all intermarriage was forbidden. The Torah phrases the prohibition in an interesting way:

You shall not intermarry with them; you shall not give your daughter to his son, and you shall not take his daughter for your son, for they will turn away your son from following Me, and they will worship the gods of others…

While the Torah makes it clear that one must not marry their son to a gentile woman, or their daughter to a gentile man, it goes on to only mention that the son will be turned away from God, not the daughter. (The same is true in Exodus 34:16, “And you will take their daughters for your sons… and they will make your sons go astray after their gods.”) The Sages explain that women tend to be of greater faith than me, and as the primary builders of the home, it is the women who set the spiritual tone of the family. A faithful Jewish man who marries a non-Jewish woman will, sooner or later, be led astray. Such was the case with a great many Jewish men following the Babylonian Exile, and when they finally returned to Israel, they admitted (Ezra 10:2-3):

We have broken faith with our God, and have married foreign women of the peoples of the land; yet now there is hope for Israel concerning this thing. Now therefore let us make a covenant with our God to put away all the wives, and such as are born of them, according to the counsel of Hashem, and of those that tremble at the commandment of our God; and let it be done according to the law.

“Ezra reading the Law in the hearing of the people” by Gustave Doré

From all of the above, the Sages conclude that Judaism passes on maternally. Scripture makes it clear that only the non-Jewish mother will turn a Jewish man astray, and as we learn from Ezra, only those born to “foreign women” are not part of the Covenant. Aside from this, there are a number of other practical and spiritual reasons why Judaism must be matrilineal.

Since the mother is the one actually giving birth to the child, it is pretty much clear every single time who the child’s mother is. The same cannot be said of the father. Throughout history, when raping and pillaging was unfortunately very common, and there were no paternity tests, only the mother’s status as parent was evident. This may be why the ancient Greeks and Romans tended to be matrilineal as well.

Shaye J.D. Cohen points out (see chapter 9 of The Beginnings of Jewishness) that in Athens, only the offspring of an Athenian man and an Athenian woman could have Athenian citizenship, a law introduced by Pericles around 451 BCE. If an Athenian man married a foreign woman, the children would not be Athenians. Later, the Romans similarly held that only two Roman citizens can have a child who was a Roman citizen, and if a Roman married a foreigner or someone of a lower social class, the status or identity of the child would be that of the mother.

While these rules make sense from a logical perspective, they also recognize the profound connection that a child and mother have—far superior to that of child and father. And this ties into the deeper biological, and spiritual, reasons for why Judaism is matrilineal.

The Genetics of Motherhood

When it comes to the genes and traits of children, people tend to think that they are a 50-50 mix of mother and father. We learn in school how 23 chromosomes from the father (carried by sperm cells) meet 23 chromosomes from the mother (in the egg cell) to produce a new child. We are made to believe that even if the child may look more like one parent, they are nonetheless perfectly half-half. This is completely untrue.

A karyotype showing 23 pairs of chromosomes. (Credit: National Human Genome Research Institute)

First of all, when it comes to boys, the Y chromosome of the father is far smaller and carries significantly less genes than the mother’s X chromosome. Girls do have half of their father’s and half of their mother’s genes (receiving an X from each, along with the other 22 chromosomes). However, this only refers to nuclear DNA. The cell has other forms of heritable genetic material, too, most notably in mitochondria.

The mitochondrion is one of the most vital components of any cell, and provides the bulk of a cell’s energy. The main reason that you breathe is to provide oxygen for mitochondria. They are involved in countless processes, including calcium storage, cell signalling and communication, metabolism, hormone production, the breakdown of wastes (such as toxic ammonia in the liver), and apoptosis, or cellular death. A single cell could have over a thousand mitochondria.

Mitochondria under a microscope.

These mitochondria have their very own DNA, carrying hundreds of additional genes. This DNA, called mtDNA, is passed down strictly from mother to child. A father’s mitochondria play no role. In fact, because of this, geneticists are able to trace a person’s maternal lineage fairly accurately thousands of years into the past by analyzing mtDNA. (My own mtDNA—haplogroup U6a—dates back to a woman who lived in North Africa about 1000 generations ago!)

There are multiple other cellular components that are passed down almost entirely from mother to child. Because the sperm essentially donates only its nucleus (with its chromosomes) to the egg, it is the egg cell itself that begins to divide in producing an embryo. Thus, the bulk of a person’s cellular structure comes from their mother, too. Back in university, I had one biology professor who estimated that inheritance is not 50-50, but more like 80-20. From a scientific perspective, we are far, far more like our mothers.

This is one reason why mothers have such a deep and profound connection to their child. Amazingly, scientists have recently discovered that when a woman is pregnant, DNA (and whole cells) from the child actually goes into the bloodstream and ends up in the mother’s brain! Fetal cells have also been found in lungs, muscles, and heart tissue of mothers. A mother will literally carry the DNA of her children in her body for the rest of her life.

Just as children are physically more connected with their mothers so, too, are they more spiritually connected to their mothers. (After all, one of Judaism’s central principles is that the dynamics of this physical world are only a reflection of the spiritual realms.) And this is yet another key reason why Judaism is, and must be, matrilineal.

What About Conversion?

The genetics perspective brings up an important question: what about converts? A person who converts to Judaism is, of course, a full-fledged Jew. But their DNA hasn’t changed! It goes without saying that Judaism is not genetic, and the discussion of genetics above is meant to only be an analogy for spiritual processes.

Having said that, we have an opportunity here to bust another common myth: that a person’s DNA is unchanging. People are often taught that whatever DNA they are born with, they are stuck with. If they have a defective gene for a particular condition, then they will definitely develop that condition. Today we know that this, too, is not entirely correct.

As discussed before in detail, our body has epigenetic machinery which allows gene expression to be controlled. Just because a person has a certain gene does not mean that the gene will be operational. It can certainly be “shut off”. While it was once thought that our lifestyle choices have no impact on our genes or epigenetics, new research continues to show that the choices we make have a tremendous effect on our genes. We’ve known for a long time that things like diet and physical activity impact gene expression, and now we even have evidence that prayer and meditation affects our genes.

Therefore, a person who sincerely converts to Judaism, and begins to live a Jewish lifestyle, eat like a Jew, think like a Jew, and pray like a Jew, will very likely experience changes on the genetic (or epigenetic) level as well. And these epigenetic changes are hereditary.

This is yet another reason why it is so important to convert to Judaism properly. Converting means not only converting in name, but becoming Torah-observant and living a Jewish life. Otherwise, what’s the point of the conversion? This is precisely why Orthodox conversions tends to be so difficult and time-consuming. The rabbis want to ensure (as much as possible) that the person is serious about becoming a Jew, and will actually live as one.

The process is far from perfect, and sometimes they do make it too difficult and tedious. We have addressed this in the past as well. Some point out that it was never so difficult to convert in past centuries. This is true, as the Talmud (Yevamot 47b) explains the procedure thus:

Once healed [from circumcision], we immerse him immediately; and two scholars stand above him, and teach him a few easy commandments and a few difficult commandments. Once he has immersed and come up from immersion, he is part of Israel for all matters. If the convert is a woman, women sit her in the water up to her neck and two scholars stand outside, and teach her a few easy commandments and a few difficult commandments.

That’s all it took back in those days. A person was just taught a few introductory mitzvot while already immersed part way in a mikveh. They would pick up the rest when going on to live as Jews and marry into Jewish families. Even in the time of the Rambam (Rabbi Moshe ben Maimon, 1135-1204) hundreds of years later, he codifies this exact procedure as law (Mishneh Torah, Issurei Biah 14:6). Yet, in those days just about everyone was religious (whether Jewish or not). This isn’t the case in today’s secular society. A person who converts to Judaism wouldn’t necessarily learn how to be a Jew by simply marrying into a Jewish family. It is necessary to carefully teach them everything beforehand.

It is just as necessary to determine their real intentions, and affirm their absolute sincerity. In a world where people change their identities faster than they change their socks, it isn’t surprising that Orthodox rabbis take conversion very seriously and are extremely stringent about it. It is important to keep this in mind as we continue to hear about intermarriage and the “who is a Jew?” debate in the mainstream media.

Jacob’s Sheep: Genetics and Epigenetics in the Torah

geneticsThis week’s parasha is Vayetze, where we read of Jacob’s arrival in Charan and the details of his twenty-year sojourn there. During this time, Jacob married (twice), had a dozen children, and toiled for his cruel father-in-law Laban. Laban recognized that he had been blessed exceedingly on account of Jacob’s presence, and offered him a new wage for his labour. By this point, Jacob knew not to trust the sly Laban, and asked simply for ownership of all the speckled and spotted sheep. Since these imperfect-looking sheep were few in number, Laban readily agreed. It appears that both Laban and Jacob were well aware of the basic principles of genetics. Today, we know that sheep have 17 or so different colour alleles, and white colour is the dominant one.

For those who have forgotten high school biology: An allele is a variation of a gene. So, for example, all humans have a gene for eye colour, but have different alleles that code for the varying colours: some have alleles for blue eyes, while others have brown eyes, etc. Each person has two alleles for every gene – one from their mother, and one from their father. Certain alleles are “dominant”, while others are “recessive”. Dominant alleles are far more likely to be expressed. In humans, brown eye colour is dominant to blue eye colour, which is why some 55% of people have brown eyes, while only about 8% have blue eyes.

Basic "Punnet squares" showing the probabilities of eye colour for the children of fully brown-eyed and blue-eyed parents, and a brown-eyed parent who carries a blue allele.

Basic “Punnet squares” showing the probabilities of eye colour for the children of fully brown-eyed and blue-eyed parents, and a brown-eyed parent who carries a blue allele. (Courtesy: The University of North Carolina at Chapel Hill)

White is the dominant allele for sheep colour, so Laban assumed he was getting a terrific deal from Jacob, who was apparently ignorant of sheep genetics. In reality, Jacob knew sheep genetics quite well, and had something else up his sleeve. He only offered Laban this deal because he knew the greedy Laban would readily agree to it. So, how would Jacob outwit his father-in-law?

A Brief Introduction to Epigenetics

Jacob was evidently a far more knowledgeable geneticist than Laban, as he was aware of a concept that has only come to light in recent decades, called epigenetics. Epigenetics refers to various layers of heritability and genetic effects which are above, or outside of (hence the Greek prefix epi), the actual genetic code. In 2008, scientists defined an epigenetic trait as “stably heritable phenotype resulting from changes in a chromosome without alterations in the DNA sequence.” In simple terms: the chromosome that contains the genes is altered in some way without affecting the DNA sequence (the genetic code) itself. That alteration is heritable, too, and passed down from one generation to the next.

A number of epigenetic mechanisms have been discovered. The most common are methylations and acetylations, where small molecules are attached or removed from the DNA strand, causing it to coil either more tightly or less tightly. When the DNA coils more tightly, the gene is rendered inaccessible, and cannot be expressed. If uncoiled, the gene is exposed, and can be translated into the protein it codes for, thus expressing the trait.

Coiling of DNA and gene expression. (Courtesy: National Institutes of Health)

Coiling of DNA and gene expression. (Courtesy: National Institutes of Health)

While epigenetics is quite complicated, its implications are tremendous. What it means in practical terms is that even though a person has a certain gene, that gene does not necessarily have to be expressed, as it can be silenced through epigenetic mechanisms. For example, a person who has a gene that predisposes them to cancer, God forbid, could potentially have that gene suppressed, thus eliminating their increased cancer risk. (Though they don’t work in this precise fashion, epigenetic cancer drugs are now available.) This also applies to people who might be genetically predisposed to obesity, diabetes, Alzheimer’s, or theoretically, any trait at all. A person who has both brown and blue alleles does not necessarily have to have brown eyes (which is what we would expect based on principles of classical, or Mendelian, genetics). The brown eye allele can be silenced, allowing the blue allele to be expressed fully.

The same is true for Jacob’s sheep. While the alleles for speckled and spotted sheep are recessive, the dominant white allele can be suppressed, resulting in more speckled and spotted sheep. In the Torah, we read how Jacob took tree branches and stripped away some of their bark to expose the inner white layers so that their pattern resembled that of the speckled and spotted sheep. He then placed these branches in front of the white sheep that were mating, and this resulted in the white sheep producing more speckled and spotted offspring. In this way, Jacob was quickly able to multiply the number of irregular-looking sheep in the flocks, increasing his own wealth, and leaving Laban in utter surprise.

What does science have to say about this? Is it really possible for the white sheep to produce speckled and spotted offspring just by looking at speckled and spotted tree branches? Which factors actually affect epigenetics?

The Epigenetics Revolution

In northern Sweden lies a small, isolated town called Överkalix. This town kept detailed historical records, including births, illnesses, and deaths, as well as harvests and food prices. Researchers started poring over this data and noted a number of emerging patterns. Surprisingly, those who grew up in times of relative abundance tended to live shorter and sicker lives, while those who grew up in times of relative famine were healthier and lived longer! Even more shocking was that these traits passed on to their children and grandchildren. The grandsons of those who grew up in times of abundance lived roughly six years less than grandsons of those who grew up in times of famine!

The Överkalix study opened the door to much more research on the subject, and today we know that not only does food impact our epigenetics, but so does smoking, alcohol, exercise, and just about every lifestyle choice we make. Moreover, recent studies find that not only do our actions impact our epigenetics, but even our thoughts do! In 2013, scientists discovered that meditation affects epigenetic mechanisms and results in, among other things, less inflammation in the body, better stress responses, and faster mental processes.

TIME Magazine Feature on Epigenetics

TIME Magazine Feature on Epigenetics

Epigenetics has brought about a revolution in biology, and a new realization that we are not slaves to our genome. We are very much in control of how our genes operate, and seemingly every choice we make affects our health and wellbeing, as well as the health and wellbeing of our children and grandchildren, since these epigenetic patterns are heritable. This is one of the most enlightening and liberating scientific findings, putting each person in the driver’s seat of their biological fate. It should also motivate us to make healthy lifestyle choices because, even if we might not care so much about our own health, the health of our offspring is directly impacted by our choices.

The Return of Jacob’s Sheep

If meditation plays a role in how our genes are expressed, there is no reason why other mental processes cannot do the same. By visually exposing his sheep to speckled and spotted images, Jacob may very well have triggered an epigenetic change resulting in suppression of white alleles. Neurologists have long known that there is essentially no difference in brain patterns when a person is literally seeing something versus when they are simply visualizing the same thing. If mental visualizations like meditation can affect the epigenome, then why not actual visual displays? Armed with this knowledge, Jacob outwitted his father-in-law and became an exceedingly wealthy man.

Of course, one cannot deny God’s role in the process, as Jacob himself explained to his wives (Genesis 31:7-9):

…your father mocked me and changed my wages ten times, but God did not permit him to harm me. If he would say, “Speckled ones shall be your wages,” all the animals would bear speckled ones, and if he would say, “Ringed ones shall be your wages,” all the animals would bear ringed ones. Thus, God separated your father’s livestock and gave it to me…

Changing one’s epigenetics is not so simple! As with everything else, a little help from Above is always needed. Jacob put in his effort by exposing the animals to stimulating sights, and God took care of the rest.

Jacob's sheep are unique not only in their colour, but also in that the rams have extra horns.

Jacob’s sheep are unique not only in their colour, but also in that the rams have extra horns.

Interestingly, this week saw the arrival of 119 “Jacob’s sheep” to Israel. This ancient breed of sheep originated in the Middle East approximately 5000 years ago. They were extirpated from the land of Israel long ago, but thankfully some survived and were brought across North Africa to Europe and finally America. The rare speckled and spotted sheep are in the Holy Land once more, perhaps a sign of the forthcoming return of all of Jacob’s children to their ancestral home.