Since Gregor Mendel and Charles Darwin were contemporaries and both contributed immensely to biology, the question naturally arises, were they acquainted with each other’s work? One source I read begins with the assertion “read no further if you want a definite answer to this question.” However, the author concludes that “the unsolved mystery, therefore, remains: did Darwin actually receive a copy of Mendel’s paper and if yes did he bother to read it? (David Galton) Another source I read began “One of the great “what if” question that has fascinated historians of biology is how differently Darwinian evolution would have been received had Darwin known of Gregor Mendel, the Augustinian monk who is now considered the founder of the science of genetics.” (John Farrell) Farrell continues “But Darwin never knew of Mendel. He never read his published findings outlining the basic laws of genetic inheritance.” A pretty bold statement to be sure. Now for a third source, “There is clear evidence that Mendel read “The Origins of Species” and mounting evidence that Darwin had heard of Mendel’s work. Their places in the scientific world were a universe apart.
Darwin shocked the world in 1859 when the Origins of Species was published. It was an instant hit. Mendel presented his paper. Versuche uber Pflanzen-Hybriden (Experiments in Plant Hybridization) in February 1865 to the Brunn Society of Natural History in Brunn, Austria which remained in obscurity until 1901 when copies were discovered independently in Europe and in the United States More about that later. Whereas Darwin’s book sold out almost immediately, there were no question asked, nor discussion made when Mendel finished his presentation. Some authors and textbook authors have suggested that not one of the 40 or so present had any idea what he was talking about. Indeed genetics wasn’t even in its infancy yet. However, there were some prominent scientists in attendance including the noted astronomer and botanist G. von Niessl, Karl Whilhelm, a Swiss a botanist and geologist, and German botanist and embryologist Matthias Schleiden who also worked on the cell theory. Hugo Iltis who wrote The Life of Mendel suggests some reasons for the silence. Mendel’s presentation was upstaged by an immediate discussion of Darwin’s book and Mendel’s paper was full of mathematical calculations and ratios. Having read all 40 pages I can attest to that.) Applying mathematics to biology was a concept before its time. The hot topic for biologists at the time was to try to explain the extraordinary multiplicity of living forms. Mendel wasn’t opposed to the theory of evolution. He had read Origin of Species and other related books. He even wrote notes in the book’s margins. Mendel had said that his experiments were designed to “support or illustrate the influence of the environment on plants”‘ in support of Lamarck’s theory of blending characteristics which held that when gametes combine there is a mixing of hereditary material that produces a blend like mixing black and white ink to form gray ink. Thus a mating between a black animal with a white one would result in a gray one and likewise between two plants, one producing black flowers and one with white flowers.
Thus, F2 (second generation) plants and animals as well as future generations would also be gray since once blended colors could never change. Obviously, this theory ignored skipping generations, a well observed phenomenon.
Blending inheritance presented special problems for Darwin and other evolutionists since evolution depends on natural selection. If blending inheritance was true, hereditary variations would disappear resulting in complete uniformity. Thus, matured relation would have no new material on which to act and evolution would cease to occur. (Curtis and Barns) Back to Mendel’s experiments; even though he expected such results, his experiments suggested much different results. Mendel concluded that “This much already seems clear to me, that nature does not modify species in any such way, so some other force must be at work.”
Mendel ordered 40 copies of his paper to send to famous European scientists. By then Darwin certainly qualified as one of the most famous. This was in 1863, four years after origin of species was published. Reprints were also sent to Schleiden and the Swiss botanist Karl Wilhelm.
Differences in their work
| 1)Darwin wrote volumes meant to convince by sheer size | 1)Mendel wrote 40 pages | ||||||
| 2)Darwin proposed natural selection occurring over millions of years | 2)Mendel proposed artificial selection to demonstrate genetic inheritance in. only a few generations | ||||||
| 3)Darwin focused on the variability of species | 3)Mendel’s results indicated mathematical and constancy of inheritable traits | ||||||
‘”It requires, indeed, some courage to undertake a labour of such far-reaching extent This appears, however, to be the only right way we can finally reach the solution of a question the importance of which cannot be overestimated in connection with the history of the evolution of organic forms. This paper now presented records the result of such a detailed experiment…. Whether the plan upon which the separate experiments were conducted and carried out was the best suited to attain the desired end is left up to the friendly decision of the reader”’ –Gregor Mendel And what a legacy it has been. Approximately 10 years conducting a single long experiment involving over 27,000 plants.
Now we come to the real heart of this essay. Did Mendel read Darwin and did Darwin read Mendel? According to David Galton “Mendel had, of course, read and studied the Origin of Species in the German translation as soon as the second edition appeared in 1863. He bought most of Darwin’s other books and studied them carefully making frequent annotations. Of the 40 copies of Mendel’s work a few ended up in learned societies throughout Europe including the Royal Society. The Linnaean Society, and Greenwich Observatory in Britain.
If Darwin did receive and read Mendel’s article, he would have found a detailed analysis of the frequencies observed from different inherited traits. However, Mendel’s results were in the form of mathematical tables and Darwin felt that there was no place for mathematics in biology. Some of Mendel’s final remarks give strong implications that he had discovered laws that could predict the appearance of different hybrid characters in successive generations of the edible pea and probably would apply to other species as well. Mendel’s conclusions virtually eliminated blending inheritance which Darwin apparently accepted.
Even if Darwin didn’t receive a copy of Mendel’s paper, be had other chances to read Mendel’s work. Herman Hoffman, a professor of Botany had written about plant hybrids in 1869 and included a long section of Mendel’s paper. Darwin’s copy of the book, now preserved in the Cambridge University Library contains handwritten remarks in the margins of surrounding pages but not page 52 the one with references to Mendel.
Furthermore, a certain George Romannes in preparing an article for the Encyclopedia Britannica on plant hybridization requested Darwin to suggest names of eminent botanists who should be included. Darwin’s answer included sending him a book by William Focke who summarized Mendel’s work on pages 108-111. But apparently Darwin never read it. Darwin had done plant breeding experiments using over 50 plant species but never with the idea of studying the transmission of plant characters… The problem of plant hybrid vigor and its role in evolution…. and whether seeds from cross- fertilized flowers would produce superior plants than seeds derived from self- fertilized flowers interested him more. (David Galton) According to John Farrell, Darwin states that “the laws governing inheritance are quite unknown.” (1st edition) Farrell quoting an article by Daniel J. Fairbanks and Scott Abbott writes that while Darwin knew Mendel, Mendel not only knew of Darwin’s work but even adopted some of his terminology and concepts in evaluating his experiments. Fairbanks-and Abbot examined. Mendel’s German translation of Origin of Species with marginal notes and then matched Darwinian phrases that Mendel adopted for the conclusion part of his paper. The color coded words and phrases in his original paper matched those from the passages Mendel marked in his German translation. Then they used a different color to denote word and phrases not in the passages Mendel marked but found elsewhere in Origin of Species. Both types of phraseology were collectively found in the papers
Result: phraseology from passengers marked in Origin of Species are more frequent and more diverse in the 10th and 11th sections (last two) of his paper. Fairbanks and Abbott concluded that Darwin’s book influenced Mendel’s writing. Example: Ten times in the concluding remarks only, Mendel used the Darwinian term “element” and in every instance he used it to refer to his conception of material units now known as alleles. Although it doesn’t offer outright proof that Mendel had become a Darwinian, it is rather suggestive. And they emphasize that even though special creation by God was still a powerful force, Mendel’s failure to declare it as a personal belief might suggest his acceptance of evolutional theory.
And finally:
- Apparently Mendel realized how important his work was for Darwin’s theory.
- While many biologists accepted evolution during Darwin’s time many did not because of the problem of how-to combine natural selection with a convincing theory of inheritance of traits in species.
References
Ciskanik, M. Gregor Mendel and Charles Darwin: Two Men and a Theory, Magiscenter.com July 31,2020
Curtis, H. N. Sue Barness, (1989). Biology. New York: Worth Publishers Inc.
Farrell, J. How Mendel Channeled Darwin, www.forbs.com 2017
Galton, D. Did Darwin Read Mendel?QJM: An International Journal of Medicine, Volume 102, Issue 8, August 2009,