Is it possible that the two most revolutionary laws in genetics discovered in recent generations – Mendel’s Laws of Inheritance and the Law of Heterosis – appear in the Torah?

Amazingly, the answer is an unequivocal “yes.” These laws supposedly discovered in the modern era were actually revealed in the prophetic dream of Yaakov over 4,000 years ago!

Before we examine Yaakov’s dream and his struggles with Lavan, we need to first clarify a number of fundamental points – namely, the creation of the world and the deeds of our patriarchs, as described in the Torah.

The World Was Created According to the Torah

The Zohar states in a number of places that the Torah existed before the world was created. It teaches that when Gd wanted to create the world, He “looked” upon what was written in this supernal Torah, and formed the entire universe accordingly. In the Zohar’s precise words: “The Holy One looked into the Torah and created the universe.”

This means that the Torah serves as a kind of blueprint for the universe and history down to its tiniest details – all that was, is, and will be, from the dawn of creation until the end of time.

The Midrash draws an analogy to a king who designs a palace according to his future needs. His plan defines the layout of every room, office, hall, window, and so on, and how they will appear once constructed. In the same way, Gd created the world in accordance with the needs of human beings so they could fulfill His commandments.

For those of us accustomed to thinking of history as a progression of events, from earlier to later, this idea might sound radical and even strange. How can it be that all of the historical events of which the Torah speaks in great detail were already written in the Torah long before they actually occurred? For example, could Gd’s Torah contain the account of the Exodus from Egypt thousands of years before the event actually took place? How could it describe a man named Yaakov, son of Rivkah, who went to live with Lavan, before Yaakov and Lavan were even born?

These ideas only make sense if we keep in mind that the Torah is the creation of Gd, who transcends time and who knows all the mysteries of the universe and what will occur on any particular day at any particular time. Everything is revealed to Him, and He understands it all. Something that happened long ago is the same in Gd’s eyes as something that will happen in the distant future. This is why the Creator of the world can write in the fullest detail about all the events of the world well before they actually take place.

Furthermore, the Zohar and the Midrash imply not only that Gd wrote in the Torah all that would happen in the future, but that the entire universe was originally created only in accordance with the words of the Torah, on all its levels, including its most esoteric aspects. The Torah provided a grand plan for the world, and all the details of creation – the laws of nature and historical events – were generated in order for that plan to be realized. In other words, if the natural world follows certain rules, it is because this was what was determined in advance by the Creator in accordance with the “operating instructions” contained in the Torah.

It is no wonder, then, that the sages of Israel knew scientific principles that have been discovered only recently – for even science is embedded in the Torah, and is available to every Jewish person who studies Torah thoroughly, thoughtfully, honestly, and reverently.

Scientific knowledge was placed in the Torah so that it might be revealed later. On some occasions, the knowledge is encoded in the Torah, and can only be deciphered after a careful reading of an event or series of events.

Yaakov Confronts Lavan

Such case regarding the story of Yaakov and Lavan, to which we now turn our attention. This narrative is a prime example of how laws of nature are encoded in the text of the Torah. In this case, we will uncover the Torah’s understanding of two of the laws of genetics discovered only recently by modern science.

The Torah teaches that Yaakov shepherded the flocks of his uncle, Lavan, for seven years in exchange for the hand of Rachel, Lavan’s daughter, in marriage. At the end of this seven-year period, Yaakov was given Leah, instead. In order to marry Rachel, Yaakov was forced to work an additional seven years. With the birth of Joseph, Yaakov’s 11th son, Yaakov asked Lavan permission to return to his homeland (Beresheet 30:25). However, Lavan insisted that Yaakov stay and continue working, realizing that Gd would continue to bless him as long as Yaakov remained in his service. Lavan therefore offered Yaakov a new salary, and they agreed that Yaakov would take ownership of all of the “speckled and spotted” animals in the flock.

Soon thereafter, however, Lavan changed the terms and interpreted the new arrangement to mean that Yaakov would keep only the newly-born
speckled and spotted sheep. In order to avoid disagreements about which sheep were born at which time, Lavan immediately separated out all the speckled and spotted sheep and goats, and assigned them to his sons, telling them to travel a three days’ journey in the opposite direction of Yaakov. This ensured a clear and complete division between the two groups. It further guaranteed the likelihood that all animals subsequently born to Yaakov’s flocks would be of a single color, and not speckled and spotted.
A careful reading of the text reveals that Lavan constantly changed
the conditions of his agreement in order to cheat Yaakov of his rightful due.

During this time, as Yaakov found himself dealing with Lavan’s abuses, he beholds a prophetic vision (ibid. 31:10):

“And it came to pass at the time that the flock was fertile and I [Yaakov] raised my eyes and saw in a dream that the rams which leaped upon the flock were streaked, speckled, and spotted.”

At first glance, this vision was the precise opposite of what actually occurred. Yaakov saw animals mating with “streaked, speckled and spotted” animals, despite the fact that Lavan had already removed all such animals out of Yaakov’s portion.

The dream continued:

“And an angel of Gd said to me in the dream: ‘Yaakov!’ And I said: ‘Here I am!’ And it said, ‘Lift up your eyes and see that the rams upon your flocks are streaked, speckled, and spotted, for I [the angel] have seen all that Lavan has done to you.”

From this point onwards, Yaakov began to understand the depths of his father-in-law’s deception. In response, he decided to send the least fertile animals to mate with Lavan’s flock: “He sent the feeble animals [those animals least likely to be fertile] to Lavan, and the strongest [and most likely to be fertile] stayed with Yaakov’s flock.”

Yaakov prospered as a result:

“And the man’s [Yaakov’s] wealth grew and grew, and he had scores of livestock and male and female servants and camels and donkeys.”

Two difficult questions arise from this narrative:

1. Why did Yaakov see in his prophetic vision the more fertile animals as being spotted, when all he had in his flock were
solid-colored animals?

2. Why did Yaakov ensure to remove the less fertile livestock from his flocks and give them to Lavan? How did this produce the desired result, that the newborns would be spotted?

Truth be told, we cannot fully comprehend the deep reasons behind the actions of our forefathers, whose spiritual level far exceeded anything of which we can conceive. Additionally, these were all miracles performed by Hashem to protect Yaakov from the deceptions of his father-in-law. However, as always, there can be a scientific explanation for how the miracle unfolded, and it is possible that the Torah alludes here to the fascinating laws of genetics recently discovered by science.

Modern Genetics

According to the famous Israeli botanist, Professor Yehuda Flicks, two fundamental laws of genetics discovered in recent generations are reflected in Yaakov’s prophetic dream and subsequent actions: Mendel’s Law of Inheritance and the Law of Heterosis. (This is not to claim that Prof. Flicks’ findings represent the absolute truth of Scripture. The Ohr HaHayyim, in his introduction to the Torah, states that a Gd-fearing person should delve into the Torah to formulate new approaches and uncover the “70 faces” of the Torah, as long as these explanations do not contradict any of the core teachings or principles of Torah and Judaism.)

The famous genetic researcher Gregor Johann Mendel (1822-1884), who was born in Morovia, Czechoslovakia, was able to isolate pure genetic strains of both yellow and green pea plants. After hybridizing them, the first generation produced only yellow peas, whereas the second generation produced 75 percent yellow peas and 25 percent green peas. The “offspring” of the green peas were always green, but only 25 percent of the offspring of the yellow peas (bred only among themselves) remained yellow in all subsequent generations. The other 75 percent produced seeds that were yellow and green at a ratio of 1:3.

Mendel concluded that despite the inbreeding of the yellow peas, the characteristic of the green peas remained latent within them, only the yellow characteristic was dominant, whereas the green quality was recessive.

Nowadays, these hereditary factors are known as genes. In the specific case of Mendel’s peas, yellow was the dominant gene and green the recessive one. Even if a plant appears yellow, its genetic composition is actually yellow-green. And even when the plants are inbred, these strains will continue to produce 75 percent yellow and 25 percent green. Only 25 percent of yellow peas are pure yellow, without any green genes at all. On the genetic level, the rest of the peas are a mix of green-yellow.

If we removed the pure yellow strain and the green strain (which are also pure, for if they bore a yellow gene, it would immediately dominate the green element, resulting in yellow peas), and continued to inbreed the mixed yellow strains, the peas would continue to divide themselves according to the previous ratio. In even a few generations, the ratio would increase to 50 percent green and 50 percent yellow – namely, a direct reflection of the generation of the “parents.” This principle is known as Mendel’s Law of Inheritance.

The Law of Heterosis was discovered only recently. According to this law, heterozygotes manifest stronger fertility traits than monozygotes. In other words, entities with mixed genetic strains are more likely to be more fertile than single genetic strains. For example, if we had before us a flock of animals with a solid color, and one group within the flock included a mixed gene pool of both solid and spotted animals, this mixed group would be more fertile than the dominant solid color group.

There are hints to both these genetic laws in the angel’s words to Yaakov, as well as in Yaakov’s actions after beholding this vision. The angel told Yaakov, “Lift up your eyes and see that the rams upon your flocks are streaked, speckled, and spotted.”  Yaakov is instructed to “see” the truth that even though the animals appear to be of a single color, their “internal” colors (i.e., genetic compositions) are streaked, speckled, and spotted. As a result, these are the colors of the offspring they will reproduce. According to Mendel’s Law of Inheritance, if we were to isolate the solid color animals with dominant spotted genes and compel them to mate with each other only, the spotted genes would begin to take over the solid color genes, resulting in spotted offspring.

How, though, did Yaakov know which animals had recessive or dominant genes?

Here is where we apply the Law of Heterosis, according to which the animals who mated most productively were the ones with the dominant spotted genes, despite their solid color. Yaakov divided the animals in his flock accordingly, as the Torah relates: “He sent the late-bearing animals to Lavan, whereas the quickest to conceive stayed with Yaakov’s flock.” Meaning, Yaakov took the least fertile animals, which, according to the Law of Heterosis, are genetically a single-color strain, and quickly sent them to Lavan’s flock so they would not impregnate his own flocks and produce single-colored stock. He took the most fertile animals, which he knew contained the spotted genetic strain, with his herds so they could produce spotted animals, which he could then keep as per his agreement with Lavan.

In this way, Yaakov recouped the wages of many years of labor which had been stolen by his father-in-law.

Only thousands of years later did the world of science discover Mendel’s Laws of Inheritance and the Law of Heterosis, which the Torah already demonstrated through the actions of Yaakov.

Adapted from an article that appeared in The Jewish World of Wonders.Rabbi Zamir Cohen is the founder of the Hidabroot organization and has written several books on the topics of Jewish thought, and law including his bestseller, The Coming Revolution.