The following is based on part 12 of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). This one is about genetics:
Gregor Mendel was a farm boy who became monk. He joined the Augustinian order in Brno, the second largest city in what is now the Czech Republic. They sent him to the university of Vienna to get a teaching degree. The university said he “lacks insight and the requisite clarity of knowledge” and failed him in 1853.
A few years later he began to do experiments on pea plants. People assumed that if you cross a tall pea plant with a short one you get pea plants of middling height. Instead of assuming Mendel tried it: he found that you get nothing but tall pea plants! And if in turn you cross those tall pea plants you get 75% tall pea plants and 25% short ones.
Why? Mendel said it was because each plant gets a height particle – what we now call a gene – from each parent. In the first generation of his experiment, each plant had a tall gene and a short gene, so all of them were tall. But in the second generation one fourth received two short genes and so they were short.
He had discovered the gene, one of the greatest discoveries in the history of science. It sank like a rock. Mendel was a nobody: the important science journals in France and Britain did not print it. In 1866 he had it printed in a Brno science journal and there it sat unknown to the top people in science till 1900.
The next big discovery was printed in Nature in 1953, so it was known instantly worldwide: DNA and how it works. DNA is what genes are made of. James Watson and Francis Crick beat out Linus Pauling in discovering how it works.
DNA is a double molecule, each half the mirror image of the other half. When the molecule splits in two, each half can create its missing half. But there is more: it is a long molecule that contains smaller molecules called bases: adenine, guanine, cytosine and thymine. These become in effect the four letters – A, G, C and T – of the language that genes are written in, containing the instructions of how to build everything in the body.
But genes and DNA are not enough to account for life as we know it. You also need:
- Sex, which mixes genes in new ways. Till sex came along life did not progress beyond the level of pond scum.
- Human sexual selection, which speeds it up even faster: humans, compared to other animals, put far more thought into choosing who they have children with. They also have taboos against incest which prevents a few older males from getting all the females and lowering the rate at which genes mix.
As John Donne said:
Love’s mysteries in souls do grow
But yet the body is his book.
See also:
Sexual selection (formerly my chosen specialised subject) is certainly an important factor in evolution, but by no means restricted to humans. It occurs in most, if not all, sexual species.
Sexual selection has two components, intra-sexual (usually male) competition and mate choice (usually female).
On the other hand, we really have no need to explain why evolution is fast. What really needs explanation is why evolution is much, much slower than we would expect. Natural selection (including sexual) changes populations extremely rapidly, yet changes in the fossil record are slow. We don’t really know why but it is likely that selection rapidly runs out of relevant genetic variance.
Thank you for your excellent blog.
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I hope this comment is not considered off topic.
Mendel’s story is a justification for looking for more than just means and test scores for admission to college. I recently finished a degree at a university that was a highly rated design school. In their showcases of the students work, there was little innovation or creativity. The designs that I felt were more creative were from the foreign students. I felt that the school needed more diversity, since most students were white upper middle class. Professors use to dealing with a particular kind of student, would be befuddled when someone’s mind works differently, which apparently Mendel’s did.
Too bad he didn’t live to see his work recognized.
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Bronowski’s biographical sketch of Mendel seems a bit weak and misleading:
“Gregor Johann Mendel was born on July 22, 1822…He was ordained into the priesthood in August of 1847…In 1849, he was assigned to a secondary school in the city of Znaim. It was there that he took the qualifying examination for teacher certification and failed. ”
“In 1851 he entered the University of Vienna to train to be a teacher of Mathematics and Biology. It was at the University of Vienna that he developed his skills as a researcher which he utilized later in his life.”
“Mendel returned to teaching in Br�nn in 1854. Two years later he again attempted the state certification examination. He became quite ill, perhaps as a result of severe debilitating test anxiety, and he withdrew. ”
“He did attempt to take the examination again, but returned to Br�nn in 1856 where he continued to teach part-time.”
The Teacher Certification Exams given today are no better than those given in Mendel’s day. For the most part, teaching itself is controlled through the use of mandated Dept. of Education curriculums. Teachers, for the most part, are prohibited from teaching “creatively.” — unless they work at non-government-run or non-church-run schools.
Meanwhile, there is a big difference between science and other fields. In science, researchers are always looking for the truth. They may go off track — as they have with Global Warming — but the truth eventually works its way out.
Mendel’s work may have been ignored from 1866 to 1900, but clearly the value of his work was eventually recognized. When others finally grasped the meaning and significance of his insights, the stage was set for rapid advancement.
Where will the study of genetics take us? To the Brave New World? To the world of Blade Runner? Or to a world where the control of genes is used purely for good?
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hathor, you wrote:
“Mendel’s story is a justification for looking for more than just means and test scores for admission to college.”
Colleges look at grades and test scores. However, if a student is applying to art school — visual, performing, etc. — then evidence of the student’s artistry is part of the admission process.
You wrote:
“I recently finished a degree at a university that was a highly rated design school. In their showcases of the students work, there was little innovation or creativity.”
At the undergraduate or graduate level, there is reason to expect creativity in design competition. But in science, the body of knowledge is so huge that no one is breaking new ground until reaching the doctoral level. However, there are plenty of science talent searches and competitions for high school students in the US.
Intel runs a big one. In addition, high school students from all over the US are conducting innovative research as part of their preparation for college. Of course the numbers of kids doing original research are small. But the kids are out there, and their work is getting them noticed by colleges.
You wrote:
“The designs that I felt were more creative were from the foreign students. I felt that the school needed more diversity, since most students were white upper middle class.”
I’m getting visions of The Fountainhead.
You wrote:
“Professors use to dealing with a particular kind of student, would be befuddled when someone’s mind works differently, which apparently Mendel’s did.”
Befuddled? At the college level? I doubt it. I’ve been around plenty of inventive engineering students and they were given lots of room to exercise their creative impulses.
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Mendel was Austrian not German…couldn’t finish reading because of that err.
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That was my mistake. Bronowski never said he was Austrian or German or what, so I took it out.
Mendel was born in what is now the Czech Republic near the Polish border. The Wikipedia says he was an ethnic German. He was Austrian only in the sense that the the Czech Republic in those days was ruled from Vienna by the Austro-Hungarian empire.
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As a biology major, Ive been introduced to Mendel and his contributions more times than I can count.
The general consensus is that he was an Austrian monk, period.
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Another genius denied. Hm… That’s quite often the case, isn’t it? Thomas Edison and Albert Einstein come to mind, as well.
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Are you sure this is true? There seems to be a lot of factors influencing sexual selection across much of the animal world.
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