The Evolution of Evolution”*
If there is a grand truth about science, it is that science is a collective enterprise. Researchers trade ideas, borrow any that come their way. Colleagues and rivals are indistinguishable, borrowing becomes what in other circles goes by the name of theft; opponents are generally recognized, sometimes not, more often in the vast flood of papers, lost. Vanishing few are the discoveries made by a single individual. Strange, then, that even today the media so often portrays the great advances of science as springing fully formed from the brow of towering geniuses who work in splendid isolation.
No better example can be found than in the current celebration of Charles Darwin’s two-hundredth anniversary. Certainly no scientific theory of the last four hundred years has had as much impact on human thought and culture as evolution. Yet, the shallowness of the reportage merely highlights the fact that more than any other theory, evolution has been deprived of a public genealogy.
Some schoolchildren do know that the famously dilatory Charles Darwin was spurred to complete his Origin of Species upon receipt of an essay by Alfred Russell Wallace containing “exactly the same theory as mine.” Less well known is that Charles was indebted for many of his ideas to his own grandfather, Erasmus, whom he conspicuously failed to acknowledge.
Born in Nottinghamshire in 1731, Erasmus Darwin was the seventh child of Robert and Elizabeth. He studied medicine at Cambridge and Edinburgh, became the most successful physician in England, meanwhile inventing a plethora of devices that included a horse-drawn carriage whose steering mechanism is that used by automobiles today. His experiments in electro-shock therapy stimulated not only the livers of his patients but the imagination of Mary Shelley and her writing of Frankenstein. Friend of Ben Franklin, Erasmus was the first to understand cloud formation, made contributions to geology, was an early convert to Lavoisier’s theory of combustion and became, to top it off, the leading English poet of the day. He also proposed the theory of evolution.
As early as 1770 fossils unearthed during the construction of the Harecastle tunnel convinced Erasmus that life as we know it was descended from a common ancestor. To the family coat of arms, three scallop shells, he even added the motto E conchis omnia (“everything from shells”). The first of his ideas he published in two long and wildly successful poems, The Loves of the Plants and The Economy of Vegetation, which not only make it clear that he believed in a common ancestor of man, but in something like the big bang theory. His ideas are further elucidated in the posthumously published Temple of Nature and his 1000-page treatise, the Zoonomia of 1794.
While natural selection may not be quite announced in the Zoonomia, Erasmus observes that males of certain bird species are armed with claws which the females lack and concludes these weapons cannot be for fighting external enemies; they are for fighting “for the exclusive possession of the females.“ He goes on to say, “The final cause of this contest amongst the males seems to be, that the strongest and most active animal should propagate the species, which should thence become improved.” Erasmus also reiterates his belief that all creatures descended from common “filaments,” or molecules. In the most celebrated passage of the Zoonomia he asks
…would it be it be too bold to image that in the great length of time since the earth began to exist, perhaps millions of ages before the commencement of the history of mankind, would it be too bold to image that all warm-blooded animals have arisen from one living filament, which THE GREAT FIRST CAUSE endued with animality, with the power of acquiring new parts, attended with new propensities, directed by irritations, sensations, volitions, and associations; and thus possessing the faculty of continuing to improve by its own inherent activity, and of delivering down those improvements by generation to its posterity, world without end.
Erasmus’s willingness to accept geological timescales for the age of the Earth was incredibly foresighted. In this he was more modern than Charles, who had to contend with physicists who refused to accept a geologic age for the Earth. (It goes without saying that here Erasmus outdistances creationists of our own era.)
On the other hand, his idea that species might mutate through “volitions” does seem to veer in the direction of Lamarck, who followed a few years later and believed that characteristics acquired during the lifetime of an organism ( a giraffe stretching its neck to obtain food) would be inherited by its offspring. Erasmus, though, apparently had more general mechanisms of heredity in mind, understanding that the differentiation of birdbeaks “had been gradually produced during many generations by the perpetual endeavor of the creatures to supply the want of food.”
To some extent it may indeed have been due to a confusion with Lamarck that Darwin’s ideas were discredited, though by the time Zoonomia was published, England was soon to go to war with France and nobody wanted to hear about the brotherhood of man or atheistic theories.
Why Charles Darwin, born in 1809, was so reluctant to acknowledge his own grandfather is a matter for psychologists. In his Autobiography, Charles overflows with praise of George Lyell, about whose Principles of Geology he says, “The science of Geology is enormously indebted to Lyell–more so, as I believe, than to any other man who ever lived.” As for his grandfather, however, we know that while a student at the University of Edinburgh Charles studied the Zoonomia closely. Yet the only mention of it in the Autobiography comes during a conversation with Robert Grant, a lecturer at Edinburgh who tried to convert Charles to the views of Lamarck and Erasmus. “I listened in silent astonishment, and as far as I can judge, without any effect on my mind. I had previously read the Zoonomia of my grandfather, in which similar views are maintained, but without producing any effect on me. Nevertheless, it is probable that the hearing rather early in life such views maintained and praised may have favored my upholding them under a different form in my Origins of Species. At this time I admired greatly the Zoonomia; but on reading it a second time after an interval of ten or fifteen years, I was much disappointed; the proportion of speculation being so large to the facts given.”
In his defense, Charles took pains to point out that Erasmus was the wild theorizer and he the meticulous observer. “I look at a strong tendency to generalise as an entire evil,” Charles once wrote to a close friend. Indeed, perhaps the main reason The Origin of Species of 1859 occupies its deserved position in the canon of great and influential books is that it overflows with facts and observations. Yet Origin also overflows with hundreds of names. Not one is Erasmus.
At the age of seventy, Charles had a change of heart and penned a biography of his grandfather, publishing it as a 127-page preface to an 86-page essay on Erasmus by Dr. Ernst Krause of Germany. The attempt backfired. Not only did it touch off a lifelong feud with family friend Samuel Butler, author of Erewhon, who correctly accused Darwin of gross tampering with Krause’s essay as to minimize Erasmus’ contributions, but Charles’ own essay as published damns Erasmus with faint praise. Of his evolutionary ideas Charles says almost nothing, deferring that task to Krause. It turns out that Charles had allowed his daughter Henrietta, who hated everything Erasmus stood for, to censor the work. All favorable passages, including the final peroration in which Charles praised Erasmus for his generosity and prophetic spirit, were cut. It was only in 1958 that Darwin’s granddaughter Nora Barlow restored some passages and appended correspondence relating to the controversy. Well, as Charles put it to T.H. Huxley, “the history of error is unimportant.”
Erasable. Anthropologist Loren Eiseley* has pointed out that Origin was already in proof when Lyell himself caught Darwin in the act of ignoring Lamarck. In the first edition, Darwin omitted “by inadvertence” Wallace’s name in the final summary, despite the historic joint announcement and publication of their papers. Of course, as Darwin told Lyell, he “never got a fact or idea” from Lamarck. One wonders what Charles would have said about Edward Blyth.
In fact he said nothing. Blyth (1810-1873) was a friend of Darwin’s and a pioneering naturalist who wrote major papers on heredity and zoology for The Magazine of Natural History. In those papers Blyth clearly saw the importance of variation and sexual selection, although he mistakenly interpreted natural selection as a force tending to stabilize species, rather than to diversify them. In 1835 Blyth wrote, “…as in the brute creation, by a wise provision, the typical characters of a species are, in a state of nature, preserved by those individuals chiefly propagating, whose organisation is the most perfect, and which, consequently, by their superior energy and physical powers, are enabled to vanquish and drive away the weak and sickly, so in the human race degeneration is, in great measure, prevented by the innate and natural preference which is always given to the most comely…”
Could Darwin have been unaware of Blyth’s work? Well, they were friends. Furthermore, by tracing Darwin’s own footnotes Eiseley has been able to determine that Darwin was in possession of and read the same issues of Natural History in which Blyth’s papers appeared. Yet, in Origin Darwin repeats many of Blyth’s assertions almost verbatim without acknowledgement and Eisley makes a convincing case that it was Blyth, not Thomas Malthus as Darwin claimed, who started him on the road to natural selection.
If any other precursors to evolution are now forgotten more than Edward Blyth they must be Sir William Lawrence (1783-1867) and Patrick Matthew (1790-1874).* Lawrence is forgotten intentionally because his book Natural History of Man, published in 1819, came to conclusions so distasteful to those times (and in part to ours) that it was suppressed. A professor at the Royal College of Surgeons and called by T.H. Huxley “one of the ablest men whom I have known,” Lawrence did not arrive at natural selection and believed that species were fixed. Nevertheless, he emphatically rejected Lamarck’s dominant notion of acquired characteristics and stated that 1) The physical, mental and moral differences in the races of man are hereditary; 2) The different races have arisen through mutations; 3) Sexual selection has improved the beauty of advanced races and governing classes; 4) “Selection and exclusions” are the means of change and adaptation; 5) The study of man as an animal is the only proper foundation for research in medicine, morals and even in politics. “The diversification of physical and moral endowments which characterize the various races of man,” he wrote, “must be entirely analogous in their nature, causes, and origin, to those which are observed in the rest of the animal kingdom and therefore must be explained on the same principles.” The origins of man “cannot be settled by an appeal to the Jewish scriptures.”
Lawrence’s insistence on treating man as an animal utterly offended England of his day. The Church was outraged, Lawrence was repudiated by the leaders of his profession. The Lord Chancellor refused to allow copyright for the book on the grounds that it contradicted Scripture. So crushed was Lawrence by the affair that he withdrew Natural History from circulation and clammed up for the rest of his life. Nevertheless, both Darwin and Wallace read Lawrence. Darwin does not seem to have been impressed but Wallace was. Indeed he may well have taken Lawrence’s ideas to their logical conclusion in postulating natural selection. We also know that Blyth cited Lawrence as a major source and in that way he indirectly influenced Darwin.
When Charles learned of Patrick Matthew’s book, On Naval Timber and Aboriculture, published in 1831, he himself wrote, “Mr. Patrick Matthew… gives precisely the same view on the origin of the species…as that propounded by Mr. Wallace and myself…He clearly saw…the full force of the principle of natural selection.”
Certainly Matthew, writing twenty-eight years before Darwin, states, “…As the field of existence is limited and pre-occupied, it is only the hardier, more robust, better suited to circumstance individuals, who are better able to struggle forward to maturity, these inhabiting only the situations to which they have the superior habit of adaptation and greater power of occupancy than any other kind …This principle is in constant action…those only come forward to maturity from the strict ordeal by which Nature tests their adaptation to her standard of perfection and fitness to continue their kind of reproduction.” Matthew however, in contrast to Darwin, was a catastrophist and viewed evolution as being spurred on by geologic upheavals, interrupted by eons of stability (in this he seems to share certain ideas of modern theories.)
Little is known about Matthew and it does not appear that Darwin knew of his work before publication of Origin of the Species. Nevertheless, while with hindsight we tend to view naturalists such as Lawrence and Matthew as merely highlighting Darwin’s correctness, in their own time they did not consider themselves Darwin’s precursors. They should be credited for their own accomplishments and, as we celebrate Darwin’s two hundredth, let us remember that science would look very different if shadows never haunted the wings.
* A different version of this essay appeared in Everything’s Relative and Other Fables from Science and Tecnology (Wiley, Hoboken, NJ, 2003).
* Loren Eiseley, “Charles Darwin and Edward Blyth,” Proceedings of the American Philosophical Society 103, 94-158 (1959).
* See, e.g., Kentwood Wells, “Sir William Lawrence: a study of pre-Darwinian ideas on heredity and inheritance,” and “The historical context of natural selection: The case of Patrick Matthew,” J. Hist. of Biology 4, 319-361 (1973); 6, 225-258 (1973) and references therein.