Category Archives: Torah & Science

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.

 

The above is an excerpt from Garments of Light: 70 Illuminating Essays on the Weekly Torah Portion and Holidays. Click here to get the book! 

Are There Really Just Four Non-Kosher Animals With One Sign?

This week’s parasha is Shemini, “eighth”, referring to the eighth day of the Mishkan’s inauguration ceremony. On this day, the sons of Aaron, Nadav and Avihu, brought an unsanctioned incense offering, and perished because of it. The Torah goes on to describe various sacrificial and priestly laws before going into the rules for kosher food.

When it comes to land animals, those that have split hooves and chew cud are kosher. Animals that do not have both signs are not kosher. The Torah then goes on to give four examples of animals that have one of the signs, but not the other: the camel chews cud, but does not have a completely split hoof; the pig has a split hoof, but does not chew cud; and the shafan and arnevet (unknown species often described as rabbits, hyraxes, or badgers), who chew cud but do not have split hooves.

The Torah uses these as examples of non-kosher animals that were present in Israel and surrounding regions in those days; animals that were familiar to the Israelites. The Torah does not state anywhere that these must be the only four non-kosher animals in the entire world that possess one sign, and not the other. Yet, somehow it became popular for Torah lecturers, particularly in the world of kiruv (Jewish outreach), to suggest that thousands of years ago, the Torah predicted there are only four such animals in the whole world, and to this day, no other animals have been found that only offer one sign. While ancient Jewish literature has plenty of amazing foresight into scientific matters – which may be used to show people its deep wisdom and divinity – this particular argument is highly flawed. The truth is, there are other animals that have one of the two signs, and not the other. Let’s take a look at a few examples.

Hippos & Llamas

A famous problem was the case of the hippopotamus. A hippo has the same foot structure as a pig, and like a pig, does not chew its cud. (While it is herbivorous, eating mostly grass and aquatic plants, hippos have been noted to even eat meat on occasion.) A hippopotamus is thus a perfect example of another animal that has split hooves but does not strictly chew cud.

Hippo and Pig Hooves

Hippo and Pig Hooves

Despite this, people will still go out of their way to insist that the Torah’s four animals must be the only four. Some even suggest that the hippopotamus must really just be another type of pig! Of course, hippos are no more pigs than they are cows, or any other animal. In fact, today scientists know that hippos are most closely related to whales (and DNA analysis confirms this).

On the other side of the spectrum are the animals that chew cud but do not have fully-split hooves. The llama and alpaca are good examples. Once again, there are those that will insist these must be just another type of camel – even though they have wool, and no humps, are commonly used for their meat, and were once thought to be closer to sheep.

Huacaya Alpaca

Huacaya Alpaca

Some might argue that since camels and llamas are officially grouped by scientists in the same family of ‘camelids’, they can be thought of as being basically the same. In reality, a zoological ‘family’ could be a vast group with very different species. For example, donkeys and horses are in the same family, yet no one in Biblical times (or today) would consider them “the same”. In fact, a donkey has a totally different status in Judaism than a horse, and a firstborn donkey is required to be redeemed in Jewish law. No rabbi would permit a horse to be redeemed in place of a donkey!

Camelids: Bactrian Camel, Llama, and Vicuana

Camelids: Bactrian Camel, Llama, and the deer-looking Vicuna

Truth in Kiruv

At the end of the day, the debate over the four animals listed in the Torah matters very little. The Torah does not claim these are the only four animals, so there is no need to make that conclusion. The problem is when people do make that conclusion, then use it as a proof to convince others of the divinity of Judaism. Those victims might be convinced initially, then go on to do their own research and discover that the “proof” was actually false, which may then serve to push them away from Judaism altogether.

Besides, there are many more solid arguments from ancient Jewish literature that can be used instead. Here are a couple of much better ones:

בְּשַׁעְתָּא דִּסְתִימָא דְכָל סְתִימִין בָּעָא לְאִתְגַּלְּיָא, עֲבַד בְּרֵישָׁא נְקוּדָה חֲדָא, וְדָא סָלֵיק לְמֶהֱוֵי מַחֲשָׁבָה. צַיֵּיר בָּהּ כָּל צִיּוּרִין חָקַק בָּהּ כָּל גְּלִיפִין… וְרָזָא דָא, בְּרֵאשִׁית בָּרָא אֱלֹהִים. זֹהַר, דְּמִנֵּיהּ כָּלְהוֹ מַאֲמָרוֹת אִתְבְּרִיאוּ בְּרָזָא דְאִתְפַּשְׁטוּתָא דִנְקוּדָה דְּזֹהַר סְתִים דָּא

זוהר חלק א (בראשית) דף ב/א, טו/א

“When God began to create, He first made a singular point, with which he then formed all formations, and carved out all things… And the secret of ‘In the beginning, God created…’ [Genesis 1:1] is radiance [zohar], from which all Utterances were created, in the secret of the expansion of the point of radiance.”

The Zohar, a mystical commentary on the Torah first published in the 13th century (based on much older teachings) describes that creation began from a singular point of radiation that expanded to give rise to all things. This is precisely what science tells us today with the Singularity that spawned the Big Bang, and the cosmic expansion and cooling that followed, giving rise to all matter. (See ‘Torah on the Big Bang and the Age of the Universe’ here for more.)

The Zohar also tells us:

דהא כל ישובא מתגלגלא בעגולא ככדור, אלין לתתא, ואלין לעילא, וכל אינון בריין משניין בחזוויהו משנויא דאוירא, כפום כל אתר ואתר

זוהר חלק ג (ויקרא) דף י/א

“… The entire planet is rotating in a circle like a ball. There are people below, and people above, all different in appearance due to the different atmospheres of each land.”

At least seven centuries ago, the Zohar already taught that the Earth is spherical, and more significantly, that it is rotating (which scientists only confirmed in the 19th century – see Foucault’s 1852 pendulum experiment). The Zohar also states that despite the Earth’s spherical nature, people live above and below, without falling off the planet, and that people living in different lands have different features because of different environmental conditions, hinting at biological adaptation.

Credit: Dailygalaxy.com

Credit: Dailygalaxy.com

How Did Adam Live 930 Years?

This week’s parasha is Vayelech, which begins with Moses’ statement that “Today I am one hundred and twenty years old” (Deut. 31:2). It was the 7th of Adar, Moses’ birthday, and also his day of passing. Moses goes on to conclude his final speech to the people, then sings a deeply prophetic farewell song in next week’s portion Ha’azinu, followed by his blessings to the people in the last parasha of the Torah, V’Zot HaBracha.

Moses was the greatest of all prophets, the humblest man to walk the earth, and the central founding figure of Judaism. He was blessed with living a full and healthy life spanning exactly 120 years. It has become common today for people to wish each other 120 years of life. Why is this the specific figure? Can humans not live longer? Don’t we see in Genesis that Adam lived 930 years, Noah lived 950 years, and Methuselah (Metushelach) lived a record 969 years? What happened?

The Flood Generation

Ten generations from Adam, the world had descended into endless sin and immorality. God decreed that man’s days “will be numbered at one hundred and twenty” (Genesis 6:3). Many believe this to mean that God decreed humans will no longer be able to live past 120 years. Indeed, when looking at modern records of longevity, the vast majority of the world’s oldest people die close to 120 years. There has only been one official case of anyone exceeding 120, a Frenchwoman named Jeanne Calment who lived 122 years.

However, the traditional Jewish interpretation is that the Genesis verse above does not mean man is unable to live past 120. After all, our forefathers Abraham, Isaac, and Jacob lived long after this decree, and they lived 175, 180, and 147 years, respectively. Rather, the Jewish Sages state that God decreed the arrival of the Great Flood 120 years hence. God gave mankind 120 years to repent, and possibly avert the Flood. Noah was commissioned to go around and inspire people to mend their ways, and he had 120 years to do it.

Unfortunately, Noah failed in this endeavour, unable to bring even a single person to righteousness (as the Ark only carried his own family at the end). This is one reason for why the Flood is known in Hebrew as mabul Noach, literally “Noah’s Flood” (or mei Noach, “Noah’s waters”), as if he was partially responsible for not doing enough to inspire people to change. Because of this, many (including Rashi) have commented on the verse “Noah was a righteous and pure man in his generation” (Genesis 6:9) to mean that Noah was only righteous in his faulty generation. Had he lived in another generation, such as that of Abraham, he would not have been deemed so righteous!

We see from the Biblical chronology that after the Flood, people’s life spans steadily shorten. Moses’ older siblings Aaron and Miriam lived 123 and 126 years. Moses died at 120, and this appears to have become the new limit. After Moses, there are only a few people noted to have lived longer, one of which is Yehoyada the High Priest, who lived 130 years (II Chronicles 24:16).

What accounts for this steady degeneration in longevity?

Yeridat HaDorot

The Talmud (Shabbat 112b) states: “If the earlier [scholars] were sons of angels, we are sons of men; and if the earlier [scholars] were sons of men, we are like asses…” This is one of many passages that attests to the well-known concept of yeridat hadorot, “the descent of the generations”. It is said that each passing generation falls lower and lower in its wisdom and spiritual greatness. This concept can solve the puzzle of longevity.

The body is a finite lump of matter. It is only animated and vitalized by the infinite soul within it. Thus, the greater the soul, the longer the body can live. As the spiritual potential in each generation falls, so too does the lifespan.

Moreover, it is taught that Adam contained essentially all of the souls of humanity within him (Sha’ar HaGilgulim, ch. 11). As more and more people were born over the centuries, this single universal soul broke down further and further into smaller and smaller fragments. With the exception of a number of “new souls”, the vast majority of the world’s 7 billion people are all parts of the soul of Adam. It is therefore not surprising that today’s spiritual capabilities (and with that, the lifespans) are severely limited.

At the Speed of Light

Science may offer another intriguing possibility. According to modern physics, time as we know it doesn’t really exist. The universe is one interwoven fabric of both time and space. The faster one moves through space, the slower the effects of time for that person. There is actually a formula to measure the impact of this time dilation, known as the Lorentz transformation. It is given by the equation ΔT = t√1-v2/c2 [or: t = t0 ÷ √(1-v2/c2)], where v is one’s speed and c is the speed of light.

Theoretically, the speed of light is the absolute maximum in our universe. At light speed (just under 3.00 x 108 m/s, or 300,000 km/s), time will totally stop for the traveller (if plugging it into the formula, one gets a value of zero). This seems impossible. However, if we plug in a value very close to light speed, such as 2.99 x 108 m/s, we get a very interesting result.* A person who has perceived living 80 years will have actually lived 980 earthly years! That makes Adam’s 930 years a more palatable 76, and Methuselah’s record 969 as 79. This fits in well with the verse in Psalms that a normal lifespan is 70 to 80 years (Psalms 90:10). But how could Adam and Methuselah have lived at near-light speed?

Beautifully, the Sages teach us that Adam was not a human like us. In many texts (such as Bereshit Rabbah 20:12), Adam is described not simply as a being of flesh, but rather as a being of light. Though most will interpret this metaphorically, there are those sages, such as the Arizal (for example, in Sefer HaLikutim, Bereshit, ch. 3) that interpret this quite literally. It remains to be seen what this means exactly, and if it has anything at all to do with physics, but perhaps there is much more to the idea of Adam being a man of light than we can imagine.

The article above is an excerpt from Garments of Light: 70 Illuminating Essays on the Weekly Torah Portion and Holidays. Click here to get the book! 

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*To be fair, choosing a value such as 2.99 x 108 m/s may be deemed quite arbitrary. One can also plug in finer values even closer to the speed of light, such as 2.997 or 2.9972, and so on, each of which would give a more refined result. The point of this exercise is simply to illustrate the relativity of time, and what might explain the difference in perceived years between our generations and those of the first people, through a scientific perspective.