Sunday, July 1, 2012

Darwin and Mendel

(found this article I read about a year back, I don’t ‘totally’ agree with whats written here, but its interesting none the less. And since I found it in some essay-site I guess sharing here wont play with copyright of the write-up)
I have followed with some interest the thread on Darwin and Mendel. I am currently writing my dissertation on the adult development of Charles Darwin and have perused much of his correspondence, travelled to Cambridge, England to look at original materials in the Darwin Archive, read numerous biographies, etc. As such, I believe I am somewhat qualified to make some judgment upon this dispute, clear up some confusion, and make a concluding comment.
To the best of my knowledge, Darwin never read Mendel's paper, "Versuche uber Pflanzen-hybriden", published in 1866 in _Proceedings of the Natural History Society of Brunn (Brno). These Proceedings were sent to the libraries of115 institutions, including the British Royal Society and the Linnean Society (this last might be remembered as the forum for Wallace and Darwin's joint papers on evolution in 1858). Surely Darwin had the opportunity to see or
read the paper if he wished, but it is evident he did not. There is no mention of Mendel in any of Darwin's letters, or in that of any of his correspondents as meticulously compiled in Calendar of the Complete Correspondence of Charles Darwin, University of Cambridge Press.

Mendel was not a prolific writer (he published only one other paper). Perhaps Darwin was already committed to his own theory of inheritance, Pangenesis, at this time, as some have maintained; or perhaps it was the struggle to read German, or Darwin's difficulty with mathematics, which caused him to overlook Mendel's paper. We will most likely never know. But any implication thatDarwin suppressed Mendel's paper is most certainly false. (Nor are Mendel's findings exactly what they are portrayed by popular historians of science to be. For instance, Mendel's writings predated the distinction we know today as that between phenotype and genotype. Nor did Mendel discover genes, or understand that there are pairs of alleles which are separated during meiosis. See R.C. Olby's, "Mendel no Mendelian?" (1979), History of Science, 17, pp. 53-72, as referenced by Mayribid.)

We might ask instead: 1) Why did none of the other biologists of this time recognize the importance of Mendel's findings? (Indeed, the failure of Nageli, one of the leading botanists of his time and to whom Mendel directly communicated his work, to so recognize Mendel's discoveries constitutes a subgenre within Mendel biographical studies.)
And 2) Why Mendel himself did not try to communicate with Darwin? As to the last point, Mendel was well aware of Darwin's work. (I believe Mendel visited London in the early 1870s, but have not been able to find my citation for this assertion.) Mendel's teacher and mentor, Franz Unger at the University of Vienna, had developed his own Lamarckian-styled theory of evolution in 1852 which highly interested Mendel. With the publication of  Origin of Species by Darwin, Mendel accepted Darwin's arguments regarding evolution. In Mendel's 1866 paper, he described the necessity of his experiments with varietal hybrids as an attempt to "reach the solution of a question, the importance of which cannot be over-estimated in connection with the history of the evolution of organic form." (quoted in E. Mayr, _The Growth of Biological Thought, 1982, p. 711).
Not that Mendel was in full agreement with Darwin on everything. In 1870,Mendel set out to prove that Darwin was wrong when Darwin (mistakenly) concluded that a single pollen grain was insufficient for pollination. Mendel conducted experiments and settled the issue to his satisfaction, once again reporting his findings to Nageli. Unfortunately, these experiments were not published until 1905. -- It remains to be understood why Mendel himself never thought to write to Darwin. Perhaps biographers of Mendel can more sufficiently answer this question.

One of the assertions in this thread was that Darwin was not sufficiently interested in plants, and had the hybrid experiments been reported for animals then Darwin would have suddenly taken interest. Yet Darwin was neither ignorant nor uninterested in plants. While he was not a botanist, perse, he was vitally interested in plants, in their forms and adaptations, and in the phenomena of sexual crossing, which brought to Darwin's attention some of the most unique and special kinds of sexual forms of any living thing, plant or animal. (See Darwin's books on Orchids (1862), or his essay on Lythrum salicaria, a plant which has three kinds of females and three kinds of males!) One cannot read, for instance, Darwin's long and compendious correspondence with his good friend, botanist J. Hooker, director of Kew Gardens, and not understand just how far ranging was Darwin's curiosity about plants. In fact, Darwin's contributions to our understanding of plants is far more reaching than I have even hinted at here, and includes at least four books published on botanical matters after 1872.

In July 1856, Darwin wrote to the U.S. Harvard botanist, Asa Gray, "I must say one word more in justification (for I feel sure that your tendency will be to despise me and my crotchets), that all my notions about how species change are derived from long continued study of the works of (and converse with) agriculturists and horticulturists..." (Life and Letters of C. Darwin,ed. F. Darwin, 1959, v. 1., p. 438)

Darwin's own experiments on heredity and his theory of Pangenesis were done in the late 1860s and early 1870s on rabbits and sweetpeas (!) with his cousin, Francis Galton, a well-known mathematician himself. (One could ask why Galton never read Mendel, at least before 1900??) While Darwin was mistaken in his theory, he did understand that some material entity in the body carried the information of heredity... of course, he mistakenly believed that some ontogenetically acquired characteristics might be transmitted in this fashion.

I cannot venture to guess whether or not Darwin reading Mendel would have changed matters. Ernst Mayr makes a good case in his book quoted above that it might not have changed anything. However, I question the intent behind the entire enterprise. There is a myth around men and women of genius, and Darwin's great discoveries still engender much controversy.
Even in the world of science, I do not believe that Darwin's insights have yet been fully integrated. The psychological impulse exists to pull down Darwin, and most myths surrounding him have this purpose. For instance, there is the so-called deathbed conversion of Darwin. Then, there is the myth of the young, roustabout, no-good Darwin, who, if not for a quirk of chance, would have been a pathetic failure if he had not gone on the Beagle. (My own research shoots this last myth to shreads... and while I don't want to give away the store, so to speak, one can read between the lines if you read about Darwin in the year 1831 in Browne's new biography.) Of course, there is also the Darwin who allegedly stole his theory from any number of people (Wallace, Blyth, William Wells, Patrick Matthew, etc.) Then, there is the legend that Darwin could have read Mendel, of Mendel's essay sitting in his library, or even that he turned its pages and ignored, misunderstood or generally bungled it.

Darwin made many, many errors. But there is nothing to be gained by furthering speculation around the alleged missed opportunity surrounding Mendel. I myself am always happy to acknowledge an error, or to learn new facts (as was Darwin, by the way).
If anyone has concrete, documentary evidence which directly confutes the above, then I would appreciate them notifying me. But please indicate specifically the book or journal where a
citation can be followed up.

Jeffrey Kaye, M.A., Ph.D. candidate, Clinical Psychology
The Wright Institute, Berkeley, CA