Jacob worth Noble Prize in Biology
Dr. Reuven Reuveni - IsraelOctober 10, 2013
Jacob, Rachel, Lea and Laban – the Start - Up Period
Worth
a Noble Prize in Biology
Genesis 32:13-15
If Noble Prize were
available, Jacob the father of the Twelve Tribes and the Jewish People would
have been the winner in Biology and Economy
Story in three
episodes – EPISODE ll
Jacob's Journey
from Refugee Son to Patriarch in three episodes
In three weekly
portions we read in Genesis the story of Abraham, the father of the monotheism,
the believe in one God and therefore the strong personality who brought to the
world the foundation of the Judaism, Christianity and Islam. In one weekly portion we read about Isaac his son and
seven chapters - almost 20% of Genesis, are devoted to tell us the magnificent story of Jacob –
the father of the Jewish People.
Seven years for Leah and seven for Rachel. In practical means, his work was to take care of Laban's great
herds and flocks which fed in the broad pastures about Haran, being led at
times a journey of some days away from home. These were the simple facts as the bible tells us. Is it was so simple and naïve indeed?
Practically, during fourteen years Jacob performed
breeding experiments and over the years he was the first to elucidate and
implemented the Low of Heredity that thousands years later will be known as The Mendel Lows of Heredity.
Mendel's Laws
The theories of heredity attributed to Gregor Mendel, based on his work with
pea plants, are well known to students of biology.
But his work was so brilliant and unprecedented at the time it appeared
that it took thirty-four years for the
rest of the scientific community to catch up to it.
The short monograph, Experiments with Plant Hybrids, in
which Mendel described how traits were inherited, has become one of the most
enduring and influential publications in the history of science
Mendel's
research reflected his personality. Once he
crossed peas and mice of different varieties "for
the fun of the thing," and the
phenomena of dominance and segregation "forced
themselves upon notice." He saw that
the traits were inherited in certain numerical ratios.
He then came up with the idea of dominance and segregation of genes and
set out to test it in peas. It took
seven years to cross and score the plants to the thousand to prove the laws of
inheritance! From his studies, Mendel derived
certain basic laws of heredity: hereditary
factors do not combine, but are passed intact; each member of the parental
generation transmits only half of its hereditary factors to each offspring (with certain factors "dominant" over others);
and different offspring of the same parents receive different sets of
hereditary factors. Mendel's work became
the foundation for modern genetics.
The impact of
genetic theory is no longer questioned in anyone's mind.
Many diseases are known to be inherited, and pedigrees are typically
traced to determine the probability of passing along an hereditary disease. Plants are now designed in laboratories to exhibit
desired characteristics. The practical result
of Mendel's research is that it not only changed the way we perceive the world,
but also the way we live in it.
Mendel discovered that when crossing white flower and purple flower plants,
the result is not a blend. Rather than
being a mix of the two, the offspring was purple flowered.
He then conceived the idea of heredity units, which he called "factors",
one of which is a recessive characteristic and the other dominant.
Mendel said that factors, later called genes, normally occur in pairs in
ordinary body cells, yet segregate during the formation of sex cells. Each member of the pair becomes part of the separate
sex cell. The dominant gene, such as the
purple flower in Mendel's plants, will hide the recessive gene, the white
flower. After Mendel self-fertilized
the F1 generation and obtained the 3:1
ratio, he correctly theorized that genes can be paired in three different ways
for each trait: AA, aa, and Aa.
The capital "A"
represents the dominant factor and lowercase "a" represents the recessive.
The last combination listed above, Aa, will occur roughly twice as often
as each of the other two, as it can be made in two different ways, Aa or aA.
Mendel stated that each individual has two factors for each trait, one from
each parent. The two factors may or may not
contain the same information. If the two
factors are identical, the individual is called homozygous for the trait. If the two factors have different information, the
individual is called heterozygous. The alternative
forms of a factor are called alleles. The genotype
of an individual is made up of the many alleles it possesses.
An individual's physical appearance, or phenotype, is determined by its
alleles as well as by its environment. An
individual possesses two alleles for each trait; one allele is given by the
female parent and the other by the male parent.
They are passed on when an individual matures and produces gametes: egg and sperm. When gametes
form, the paired alleles separate randomly so that each gamete receives a copy
of one of the two alleles. The presence
of an allele doesn't promise that the trait will be expressed in the individual
that possesses it. In heterozygous
individuals the only allele that is expressed is the dominant.
The recessive allele is present but its expression is hidden.
Mendel summarized his findings in two laws; the Law of Segregation
and the Law of Independent Assortment.
Law of Segregation - The "First Law"
The Law of Segregation states that every individual possesses a pair of alleles for any particular
trait and that each parent passes a randomly selected copy allele of
only one of these to its offspring. The
offspring then receives its own pair of alleles for that trait.
Which ever
of the two alleles in the offspring is dominant determines how the offspring
expresses that trait e.g.
the color of a plant, the color of an animal's fur, the color of a
person's eyes.
Law of Independent Assortment - The "Second Law"
The Law of Independent Assortment, also known as "Inheritance
Law" states that separate genes
for separate traits are passed independently of one another from parents to
offspring. That is, the biological selection
of a particular gene in the gene pair for one trait to be passed to the
offspring has nothing to do with the selection of the gene for any other trait. More precisely the law states that alleles of different
genes assort independently of one another during gamete formation.
While Mendel's experiments with mixing one trait always resulted in a 3:1 ratio between
dominant and recessive phenotypes, his experiments with mixing two traits, dihybrid
cross, showed 9:3:3:1 ratios.
But the 9:3:3:1 table shows that each of the two genes are independently
inherited with a 3:1 phenotypic ratio. Mendel concluded that different traits are inherited
independently of each other, so that there is no relation, for example, between
a cat's color and tail length.
Again, Mendel's
research reflected his personality. Once he
crossed peas and mice of different varieties "for
the fun of the thing," and the
phenomena of dominance and segregation "forced
themselves upon notice." He saw that
the traits were inherited in certain numerical ratios.
He then came up with the idea of dominance and segregation of genes and
set out to test it in peas.
It took seven years to cross and score the plants to the
thousand to prove the laws of inheritance! From his
studies, Mendel derived certain basic laws of heredity: hereditary
factors do not combine, but are passed intact; each member of the parental
generation transmits only half of its hereditary factors to each offspring, with
certain factors "dominant" over others; and different offspring of the same
parents receive different sets of hereditary factors.
Mendel's work became the foundation for modern genetics.
Is it was really so?
Following is the story as we read in Genesis 30: 37-41
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37 And Jacob took him rods of fresh poplar, and of
the almond and of the plane-tree; and peeled white streaks in them, making
the white appear which was in the rods.
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38 And he set the rods which he had peeled over
against the flocks in the gutters in the watering-troughs
where the flocks came to drink; and they conceived when they came to drink.
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39 And the
flocks conceived at the sight of the rods, and the flocks brought forth
streaked, speckled, and spotted.
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40 And Jacob
separated the lambs--he also set the faces of the flocks toward the
streaked and all the dark in the flock of Laban--and
put his own droves apart, and put them not unto Laban's flock.
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41 And it came
to pass, when so ever the stronger of the flock did conceive,
that Jacob laid the rods before the eyes of the flock in the gutters, that
they might conceive among the rods;
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42 but when
the flock were feeble, he put them not in; so the feebler were Laban's, and
the stronger Jacob's.
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43 And the man
increased exceedingly, and had large flocks, and maid-servants and men-servants,
and camels and asses.
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"And Jacob took his rods of green
poplar, and of the hazel and chestnut tree; and pilled white starks in them,
and made white appear which was in the rods. 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. And flocks conceived before the rods,
and brought forth cattle ring-straked, speckled and spotted.
And Jacob did separated the lambs" Genesis 30:
37-41.
In fact, the first breeding program ever reported, according to
Feliks (*), was thoughtfully conducted by Jacob when he was serving his
father-in-law, Laban, in order to obtain his
young and beautiful second wife, Rachel. In the above verses from Genesis, the "markers"
on the rods of green poplar, hazel, and chestnut that Jacob had
been using in the field were simply a means of masking his keen perception of
the laws of heredity that he practiced as a "clever" breeding program. These "markers" on the rods were simply to avoid the
possibility that one can mimic his real breeding program or follow his long
term research that he has been doing. Jacob apparently knew that the hybrids
derived from white sheep and black goats, which carried recessive genes of "spottedness", matured sexually
earlier than the pure monochromes in the flock. He mated the hybrids (black and white
animals), and their recessive genes emerged to produce maximally spotted
offspring in each generation, a process that thousands of years later was to be
scientifically reported and documented in the Mendelian Laws of Heredity, see
Reuveni, R**). .(
Again,
it took seven years to cross and score the plants to the
thousand to prove the laws of inheritance! From his
studies, Mendel derived certain basic laws of heredity, for Jacob it took fourteen years
though!!! Assuming that practically, during fourteen years Jacob performed breeding
experiments through which he could anticipate the color and shape of the goats
and sheep fur and therefor over the years he was the first to elucidate and
implemented the Lows of Heredity. Now Jacob is
ready to conduct his Exit Part – the agreement with Laban, regarding his
expected wages for the next six years period to work for him.
His success for the next six years is obvious and no doubt.
·
Felix, Y.
Relation
between heredity and environment, in Nature
and man in
the Bible, by Felix, Y. Soncino Press, London, 1981, 294p
·
Reuveni, R.
Biochemical
markers as tools to screening resistance against plant pathogens, 21- 47, in Noble approaches to integrated pest management, by
Reuveni R. Ed. Lewis Publishers, Boca
Raton, 1995
To
be continued in Episode |||…….
