Thursday, June 6, 2013

What Did Jacob Do?

I love convoluted passages in the Torah (Pentateuch), because in my humble opinion they are the most interesting ones. Today, I would like to direct your attention to verses of Genesis 30. 

Most of you know these verses very well, so there is no need for me to re-post them or recount them. However, let's take a look at the verses of Genesis 30:37-39 in more details:

37 ‏וַיִּֽקַּֽח־ל֣וֹ יַעֲקֹ֗ב מַקַּ֥ל לִבְנֶ֛ה לַ֖ח וְל֣וּז וְעֶרְמ֑וֹן וַיְפַצֵּ֤ל בָּהֵן֙ פְּצָל֣וֹת לְבָנ֔וֹת מַחְשֹׂף֙ הַלָּבָ֔ן אֲשֶׁ֖ר עַל־הַמַּקְלֽוֹת׃
‎38 ‏וַיַּצֵּ֗ג אֶת־הַמַּקְלוֹת֙ אֲשֶׁ֣ר פִּצֵּ֔ל בָּרֳהָטִ֖ים בְּשִֽׁקֲת֣וֹת הַמָּ֑יִם אֲשֶׁר֩ תָּבֹ֨אןָ הַצֹּ֤אן לִשְׁתּוֹת֙ לְנֹ֣כַח הַצֹּ֔אן וַיֵּחַ֖מְנָה בְּבֹאָ֥ן לִשְׁתּֽוֹת׃
‎39 ‏וַיֶּחֱמ֥וּ הַצֹּ֖אן אֶל־הַמַּקְל֑וֹת וַתֵּלַ֣דְןָ הַצֹּ֔אן עֲקֻדִּ֥ים נְקֻדִּ֖ים וּטְלֻאִֽים 
37 And Jacob took him rods of green poplar, and of the hazel and chesnut tree; and pilled white strakes in them, and made the white appear which was in the rods.
38 And he set the rods which he had pilled before the flocks in the gutters in the watering troughs when the flocks came to drink, that they should conceive when they came to drink.
39 And the flocks conceived before the rods, and brought forth cattle ringstraked, speckled, and spotted.

At this time, I'm not going to concentrate on the details of how it was done, but rather on - is it possible at all?

Here is a rather old article (1965) called "JACOB'S CATTLE AND MODERN GENETICS: A Scientific Midrash" by William Etkin. Full article located here.

In this interesting, yet highly biased and now also outdated article, author describes opinions on the matter, while giving a scientific perspective as well. Here is a little excerpt:
"The inheritance of maternal impressions as recounted in this story may be considered part of the general theory of the inheritance of acquired characters. This theory, often designated as Lamarkianism after the eighteenth century French zoologist who was its most prominent exponent, holds that changes induced in the parents' body by their experiences can be transmitted to some degree to their offspring. Thus, increased muscle power resulting from exercise improves the strength of offspring; ingrained habits become instincts after some generations.
Modern biology directly contradicts this theory. According to our present concepts of inheritance, the hereditary determinants or genes transmitted from parent to offspring are conveyed from generation to generation within the nuclei of the sperm or egg cells. External factors that modify the body cells cannot produce parallel and specific changes in the germ cells, as would be the case if acquired characteristics were transmitted. This modern viewpoint is supported not only by our knowledge of the method of genetic transmission but also by direct experimental tests of the Lamarkian hypothesis. All such tests have proved negative when analyzed critically. This is the prevailing opinion among Western scientists; some Communist geneticists differ. "
Now, the wikipedia article on inheritance of acquired characteristics gives the following information:
"Recently, researchers have reexamined this concept in light of discoveries in epigenetics and transgenerational epigenetics. The study of Heijmans et al (2008) studied people born during the Dutch Hunger Winter in 1944–1945. Adults who were conceived during the famine had distinct epigenetic marks that their siblings born before or after the famine did not. These marks reduced the production of insulin-like growth factor 2 (IGF2), affected the children's growth While transgenerational epigenetic inheritance could have occurred, the findings could also be explained by in utero modifications due to famine, rather than germline inheritance. Further, environmental stress in experimental mice that caused aggressive behavior in males caused the same behavior in their offspring, who had DNA methylation patterns changes for particular genes. 
The mechanism of transgenerational epigenetic inheritance appears to be involve long noncoding RNAs (lncRNAs), which are transcripts generally expressed from regions that are thought not to code for proteins. Some lncRNAs bind to transcripts from protein coding genes. Associated chromatin-remodeling proteins than modify local chromatin and DNA through mechanisms such as DNA methylation, suppressing gene expression.Kevin Morris's 2012 article in the Scientist discusses heritability of epigenetic changes in depth."

And one of the most modern cited articles (2012) from the wikipedia (located here) says this:
"Although biologists have generally considered Lamarck’s ideas to contain as much truth as Kipling’s fables, the burgeoning field of epigenetics has made some of us reconsider our ridicule. While no biologist believes that organisms can willfully change their physiology in response to their environment and pass those changes on to their offspring, some evidence suggests that the environment can make lasting changes to the genome via epigenetic mechanisms—changes that may be passed on to future generations."
So, as you can see, the Biblical story not only in line with modern science but also is yet to be understood by it. Therefore, at this time I would stick with the traditional interpretation which implies that it is possible sometimes to influence genetic changes through external means.

P.S. This all being said, please keep in mind that I have only general knowledge of modern genetics and animal husbandry, so my opinion is based solely on what I read.


Etkin, William. "JACOB'S CATTLE AND MODERN GENETICS: A Scientific Midrash." Tradition 7.3 (1965): 5-14.

Morris, Kevin V. "Lamarck and the Missing Lnc."

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