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Saturday, 5 November 2016

Decanonising Darwin

So, You Thought Charles Darwin Discovered Natural Selection? Wrong
Jonathan Witt 

After marshaling evidence against the theory of evolution, skeptics sometimes throw Darwin a bone so as not to seem churlish. Hey, we say in essence, natural selection does accomplish things like spreading antibiotic resistance, and Charles Darwin deserves credit for discovering the principle of natural selection even if it isn't the bauplan-building wunderkind he made it out to be.

Yet this gives Darwin too much credit.

Natural Selection Comes to Edinburgh -- Before Darwin

Long before Darwin (or Alfred Russel Wallace), James Hutton, the father of modern geology, propounded the idea of evolution by natural selection. And at least two other men followed on his heels, doing the same well before Darwin articulated the idea.

A retrospect by Paul N. Pearson in the journal Nature reports:

Following the publication of On the Origin of Species in 1859, Charles Darwin learned (and duly acknowledged) that two previous authors had anticipated the theory of evolution by natural selection. The first account to come to light was by Patrick Matthew, who had briefly outlined the mechanism in an appendix to his 1831 book On Naval Timber and Arboriculture. The second was by the physician William Wells, who had speculated on selection and human evolution in 1818.

But some 50 years ago, E. B. Bailey described a still older version of the selection theory from a 1797 manuscript by the geologist James Hutton -- now chiefly famous for his early appreciation of geological time. Unfortunately, this work, entitled the Elements of Agriculture, never appeared in print. Now a more complete, published account has come to light from 1794.

The account appears in a 1794 tome, An Investigation of the Principles of Knowledge. There Hutton wrote the following:

If an organised body is not in the situation and circumstances best adapted to its sustenance and propagation, then, in conceiving an indefinite variety among the individuals of that species, we must be assured, that, on the one hand, those which depart most from the best adapted constitution, will be most liable to perish, while, on the other hand, those organised bodies, which most approach to the best constitution for the present circumstances, will be best adapted to continue, in preserving themselves and multiplying the individuals of their race.

After quoting the passage, Pearson continues:

For example, Hutton describes that in dogs that relied on "nothing but swiftness of foot and quickness of sight" for survival, "the most defective in respect of those necessary qualities, would be the most subject to perish, and that those who employed them in greatest perfection would be best preserved, consequently, would be those who would remain, to preserve themselves, and to continue the race." But if an acute sense of smell was "more necessary to the sustenance of the animal," then "the natural tendency of the race, acting upon the same principle of seminal variation, would be to change the qualities of the animal, and to produce a race of well scented hounds, instead of those who catch their prey by swiftness." The same "principle of variation" must also influence "every species of plant, whether growing in a forest or a meadow."

One might object that this was buried deep in a long book and mostly forgotten. Perhaps, but Hutton was a major scientific figure, and he disseminated his ideas not just by book but also by lecture and conversation.

And as Pearson also notes, Wells and Matthew -- the other two men known to have articulated the idea of evolution of natural selection before Darwin had -- just so happen to have been "educated in Hutton's home town of Edinburgh, a place famous for its scientific clubs and societies."

So here's the lay of the land: Hutton was born, and died, in Edinburgh, attended the University of Edinburgh, and returned to live in the city as an adult, where he was a member of the Royal Society of Edinburgh and a leading figure in the Scottish Enlightenment. This man, the father of modern geology and a fixture of Edinburgh scientific society, propounds a theory of natural selection, and a generation later two other scientists educated in that same scientific community articulate the same idea in their works. (See a post at Genomicron by T. Ryan Gregory for more on Wells's and Matthew's early musing about natural selection.)

Darwin, keep in mind, was also educated at the University of Edinburgh. So four of the earliest articulations of the idea of natural selection are by Edinburgh men, and Darwin is the last of the four.

Darwin Rediscovers

Pearson generously reconstructs this eyebrow-raising coincidence:

It may be more than coincidence that Wells, Matthew and Darwin were all educated in Hutton's home town of Edinburgh.... Studies of Darwin's private notebooks have shown that he came to the selection principle independently of earlier authors, as he always maintained. But it seems possible that a half-forgotten concept from his student days resurfaced afresh in his mind as he struggled to explain the observations of species and varieties compiled on the voyage of the Beagle.

I suspect that's about right. I have a hard time believing that Darwin knowingly and fiendishly stole Hutton's idea and then, even in his notebooks, carefully pretended he'd never heard it before. And I find it hard to believe that the idea of natural selection was not in the air of Edinburgh when Darwin was there as a student, at least in the scientific community. Hutton was too towering a scientific figure, and the idea of natural selection popping up three times in the written works of three separate Edinburgh-trained scientists following in his wake is surely more than coincidence.

In any case, Darwin didn't discover the idea of natural selection. He either resurfaced the idea on his Beagle voyage and didn't realize he was remembering rather than discovering it; or he came upon the idea independently after three other Edinburgh men had articulated it.

And No, Darwin Doesn't Get Points for Theatrical Overstatement

But wasn't it Darwin who first realized the full power of natural selection? In his Nature article, Paul Pearson is careful to note that Hutton did not extend the idea in the way Darwin had. Hutton thought natural selection's effects were limited to generating different races or breeds within a species.

Also, neither William Wells in 1818, nor Patrick Matthew in 1831, applied the idea of natural selection beyond the species level. So the common defense of Darwin at this stage is to remind readers that it's the Victorian gentleman of Down House who gets the credit for discovering the full power and import of natural selection.

But if natural selection actually cannot produce all the biological variety we see around us, if it can only produce variety within species and just a bit beyond the species level (see Michael Behe's The Edge of Evolution), then Darwin was most original precisely where he was wrong.


Darwin did galvanize attention on the process of natural selection, but he did so in much the way those who started the legend of the Seven Cities of Gold encouraged exploration of the American Southwest. In both cases, a tall tale spurred attention and exploration. And in both cases, some worthwhile things were discovered. But the gold? Not so much.

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