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The Beginning of Genetics:
A Story about a Monk and His Peas
By Pricilla Beres
How important is genetics in today’s world? Considering that many animals,
plants and bacteria have been altered by genetic engineering for human
benefit, genetics is extremely important. Biotechnology, another term
used to describe genetic engineering, is now one of the worlds primary
industries. Society is so reliant on technology gained from genetics,
that it is difficult to imagine a time when knowledge of genes was absent.
However, before the 1860’s, this time did exist and it was not until the
dedicated work of one man, who we call The Father of Genetics, that biology
changed for good.
Gregor Mendel, Father of Genetics, lived as a monk in Brno, Czechoslovakia
(now Czech Republic) at the time of his famous research. He was involved
in teaching math and physics, although, the majority of his work centered
on botany. Specifically, Mendel focused his studies on the topic of heredity
by breeding pea plants. According to Mendel’s fellow scientists,
pea plants seemed like a silly plant to conduct research on; however,
there were many advantages to using this plant. Pea plants were available,
they could be self –pollinated and cross- pollinated, they were cheap
and they could produce many offspring. Mendel bred pea plants with character
differences to determine how traits are passed down through generations.
Some examples of the characters he used were; size, color and texture.
Since the general conclusions were similar for each character, color will
be used to describe his experiment along with the results.
To begin, Mendel started his experiment by cross-pollinating two pea plants,
one with yellow peas and one with green peas. In accordance to the theory
that was in place at this time, the cross should have produced peas that
were a mixture of yellow and green. This theory was termed Blending Inheritance
and it focused on the idea that offspring show a mixture of their parental
traits. Contradictory to this theory, Mendel’s progeny generation of pea
plants had only yellow peas! After this find, Mendel crossed the progeny
pea plants with each other. Expecting to observe more plants with yellow
peas, he was surprised to find some plants with green peas and some plants
with yellow peas. The plants with yellow peas and the plants with green
peas were in a 3:1 ratio, respectively. Through many more experiments
using color and the other differing characters, this 3:1 ratio persisted
in the second generation. Using his knowledge in math and physics, Mendel
determined that there were four combinations of dominant and recessive
traits responsible for the common ratio. This discovery excited Mendel,
and in 1866 he presented his new theory of Particulate Inheritance to
the members of the Brno Society for Natural Studies.
Unfortunately, after Mendel’s presentation, the scientific community showed
no interest or support towards his research. Scientists were confused
by the theory and could not understand why he combined the field of math
with botany. Mendel passed away in 1884 without having his research accepted.
After Mendel’s death, most of his papers were destroyed by the members
of the monastery in Brno, leaving little insight as to what inspired his
research. It took approximately thirty years for those papers that were
still around to be rediscovered.
In the 1890’s, three scientists (Hugo de Vries, Carl Correns and Erik
von Tschermark) independently arrived at the same results as Mendel. Of
the three, de Vries did the most research and therefore is acknowledged
with reviving Mendel’s work. However, de Vries did not credit Mendel in
his paper, it was Carl Correns that referenced his work on heredity. Today,
due to this rediscovery of his early research, we justifiably recognize
Gregor Mendel as the initial founder of genetics by referring to him as
The Father of Genetics.
Questions
1. Use the following attitude towards science, taken from the curriculum
guidelines for this unit, to answer question 1a and 1b:
"Be open-minded toward new evidence, and be aware of the changes it may
promote."
a. Compare this statement to the response of the Brno Society for Natural
Studies towards Mendel’s research.
b. Did Mendel possess the above attitude? Why or why not?
2. Mendel integrated math with botany to aid his research, which he later
got criticized for. Today we encourage integration of subjects in education
and research. With this in mind, describe an example from your previous
biology courses (or this one), where a biology concept is integrated with
one or more subjects.
3. Society plays a huge role in determining whether research in a particular
area should be continued, terminated, accepted or rejected.
a. Who was making the decisions in Brno and why do you think Mendel’s
research was rejected?
b. Give one argument society could make to continue AND to terminate research
in genetics.
4. Studies on Mendel’s data have shown that his results are "too good
to be true." This implies that he changed some of the results he retrieved.
a. Do you feel this discredits Mendel’s research? Why or Why not?
b. What do you think would drive a scientist to alter his/her results?
(Give two possible answers).
References
Griffiths, A. J. F., Miller, J. H., Suzuki, D. T., Lewontin, R. C., &
Gelbart, W. M. (1993). An Introduction to Genetic Analysis. USA: W. H.
Freeman and Company.
Haven, K. (1994). Marvels of Science: 50 Fascinating 5- Minute Reads.
Englewood, CO: Libraries Unlimited, Co.
Iltis, H. (1932). Life of Mendel. New York: W.W. Norton and Company, Inc.
Magner, L. W. (1994). A History of Life Sciences. USA: Marcel Dekker Inc.
Weir, J. A. (1968). Agassiz, Mendel, and Heredity. Journal of the History
of Biology, 1, 179-203.
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