Tuesday, April 21, 2020

Charles Darwin: The Power of Place III

When Alfred Russel Wallace got home, he and Darwin developed a cordial relationship but did not seem especially close. Wallace moved in with his sister's family in London and, after spending several years living in exotic and remote locations, he disliked the crowded city. Furthermore, although Darwin introduced him to his scientific peers, such as Charles Lyell, Wallace was an introvert and felt uncomfortable in wealthy, upper-class society. One senses that Darwin deliberately distanced himself from Wallace as co-discoverer of natural selection, and he avoided being photographed with him. Behind the scenes in England there was always political infighting within the scientific community as one person or group tried to outflank another with the goal of domination. In particular, the Darwin-Huxley-Lyell-Hooker group was often in conflict with a group led anonymously by Richard Owen, which regularly produced articles critical of Darwin's work.

Darwin's further research at home occasionally resulted in books. Before Wallace came back, a lesser-known naturalist, Henry Walter Bates, had returned from the Amazon, and Darwin took a great liking to him. Bates was more complementary to Darwin than Wallace, because his research helped buttress Darwin's main theory without the potential for stealing it. Bates specialized in butterflies and had noticed that some mimic others in their appearance, and that this is an example of natural selection at work. Darwin was delighted to have a non-threatening naturalist offer examples that supported his theory, and he strongly encouraged Bates to publish, which he did. Nevertheless, Wallace remained a crucial ally of Darwin, and, in an 1864 article, Wallace became the first to explicitly advance the idea that natural selection had produced modern humans. In a peripherally related manner, within scientific circles at that time, the notion that some races are superior to others was widespread. Darwin had been disappointed that some of his friends, Lyell in particular, stopped short of linking natural selection to humans, and Wallace's ideas were therefore closer to those of Darwin.

During the 1860's, Darwin's health deteriorated further, and though he was only in his fifties he looked old. With his increasing fame, prominent medical doctors visited him in Downe (the spelling had changed from Down), but none of them were able to cure him. At times he was bedridden for protracted periods. Friends, such as Henslow, and two of his sisters died. However, Darwin continued his research. Because of his celebrity, he began to socialize at the highest levels of English society, and Emma was ecstatic about getting to know the Tennysons personally. His five surviving sons initially provided him with some consternation, as they showed no particular talents, but, like him, once they started in college they generally improved by applying themselves, in much the same way that he had earlier.

His research from this period resulted in the publication in 1868 of Variation of Animals and Plants Under Domestication. In this book he attempted to explain how sexual reproduction actually works and allows traits to be passed from parents to offspring. He was not mathematically-minded and typically relied on the observation of physical attributes, which prevented him from developing a theory such as Mendel's, with dominant and recessive traits. He came up with a theory that he called "pangenesis," in which living matter contains unseen "gemmules" which carry inheritable characteristics from parents to offspring. This book was completely ignored and did nothing to enhance his reputation. In Darwin's defense, I suppose that you might say that it was a very early speculation about genetics, but it was of little value at a time when molecular biology didn't exist and the very idea of DNA was several decades away. In any case, Darwin was well aware that his theory of natural selection would remain incomplete without such understanding.

Other than the social and historical aspects described in the book, I am still finding it lacking in the sense that little is done to sum up Darwin's ideas in relation to modern science. The reader is left with the impression that Darwin had one important insight, which he maximized to the utmost by employing a pragmatic careerist strategy that made him the primary beneficiary of acclaim. In Browne's account, if you took away Darwin's privileged background and gave it to Alfred Russel Wallace, today we might be talking about Wallaceism instead of Darwinism, and Charles Darwin might be seen as an obscure Victorian hobbyist.

No comments:

Post a Comment