Tuesday, August 5, 2008

Did Dawkins get it wrong on Darwin’s delay?

Last night I watched Dawkins on Darwin on Channel 4, in the first of his three part series The Genius of Charles Darwin. It strikes me as odd that they are airing it now, when it would make more sense to do so during the bicentenary year, but then I guess it will help build the sense of anticipation for Darwin200.

In general I thought it was an accomplished entry-level piece on Darwin and evolution that will go down well with non-expert viewers (as judged from a sample of my wife and two children) and meets Dawkins’ usual high standards of linguistic craftsmanship—I particularly liked the one sentence summary of natural selection: “The race is survival, the finishing line reproduction!”

I note that Peter of The HMS Beagle Project liveblogged the show while it was actually being broadcast, which makes for fun reading and must have been hard work!

So, was there anything wrong with the programme? 

A general complaint was that it came across rather too much as Darwin hagiography (and I am a Darwin fan!) After watching the show, the naïve viewer might come away with the idea that Darwin discovered everything, from fossils to forelimb homologies, when the work of many other scientists fed into Darwin’s theorising. Also, introducing Craig Venter as the man who sequenced the human genome is likely to rile those involved in the publicly funded human genome project (but that is not detract from Venter’s sequencing efforts in general, which, through TIGR and JCVI, have shed more light on the diversity/common ancestry of life than any other comparable effort).

Moving on to specific points, alarm bells rang in my head on two occasions.

Firstly, around 9 minutes into the programme, Dawkins visits the Galapagos, where he says of Darwin:

Here he began to wonder why God would have created distinctive kinds of tortoise, finch or iguana on more or less identical small islands. Were iguanas like these related, rather than separately created. Were they cousins of the similar but different iguanas on nearby islands?

Although it is true that in the popular imagination, the Galápagos Islands are the one place on Darwin’s Beagle voyage that looms larger than anywhere else, you won’t find any evidence in Darwin’s writings for any 'eureka moment' during his visit there. His notes reveal that it was only months later, during his journey home in summer of 1836, that the Galápagos mocking birds raised his first suspicions as to the fixity of species: 

When I see these Islands in sight of each other… tenanted by these birds, but slightly differing in structure & filling the same place in nature, I must suspect they are only varieties . . . If there is the slightest foundation for these remarks the zoology of Archipelagoes will be well worth examining; for such facts would undermine the stability of Species

In fact, Darwin was more struck by how odd the inhabitants of the Galapagos were compared to the rest of the world than by the subtle differences between the inhabitants of individual islands:

The natural history of this archipelago is very remarkable: it seems to be a little world within itself; the greater number of its inhabitants, both vegetable and animal, being found nowhere else.

Plus, Dawkins’ choice of iguanas to illustrate this point struck me as a bit odd (although he avoided the obvious trap of using Darwin’s finches: see Sulloway’s dismissal of this old myth). 

The most obvious distinction among the Galapagos iguanas is between the marine and terrestrial iguanas, which are separate species, each peculiar to the archipelago. But Darwin was again struck by the restricted distribution of the iguanas

It is very interesting thus to find a well-characterized genus, having its aquatic and terrestrial species, belonging to so confined a portion of the world

I wasn’t aware that Darwin noted, within each species, any differences specific to different islands. But on checking, he does make passing references to some such differences. In the first edition of the Journal of Researches (1839), Darwin notes of the marine iguana:

On the island of Albemarle they seem to grow to a greater size than on any other.

And of the land iguana, he writes:

We will now turn to the terrestrial species (Amb. subcristatus of Gray).* This species, differently from the last, is confined to the central islands of the Archipelago, namely to Albemarle, James, Barrington, and Indefatigable. To the southward, in Charles, Hood, and Chatham islands, and to the northward, in Towers, Bindloes, and Abington, I neither saw nor heard of any. It would appear as if this species had been created in the centre of the Archipelago, and thence had been dispersed only to a certain distance. (my italics)

So, I guess one could make an argument that inter-island differences between iguanas might have has a minor influence on Darwin’s views on the origin of species, but there is no evidence that Darwin’s speculations actually occurred on the islands, rather than on the way home or even in England.

A second more troublesome point occurs much later on, at 44 mins into the film, when Dawkins states:

But he was strangely reluctant to go public with his idea… But he was acutely aware of how upsetting this flat contradiction of the religious story would be. He hesitated to publish.

Here Dawkins jumps in with both feet with his uncritical acceptance of the myth of Darwin’s delay. It is true that many recent accounts of Darwin’s life suggest that he delayed publication of his theory of evolution and that, fearful of its reception, he kept it secret for many years…

But none of this is mentioned in Darwin’s autobiography, in his obituaries or in the early accounts of his life. Only in the mid-twentieth century did these myths of “Darwin’s delay” begin to gain currency. I direct readers to a recent tightly argued paper by Darwin scholar John van Wyhe

Mind the gap: did Darwin avoid publishing his theory for many years? John van Wyhe (2007) http://journals.royalsociety.org/content/gk6840u115705166/

Here, van Wyhe highlights the many distortions and fabrications that have crept into the Darwin story over the years and shown how these are derived from biased readings of a handful of passages plucked from Darwin’s enormous written output. Darwin’s apparent delay was not down to any fears about the consequences of publishing on evolution. Instead, it was simply the accumulation of facts, ideas and arguments outrunning his ability to investigate, analyse and write about them, particularly when slowed down by illness.

Of course, not everyone agrees with van Wyhe: see this posting from a few weeks back on Genomicron. But the article by Nature journalist Lucy Odling-Smee that is refered to in the blog is hardly a match for van Wyhe’s tightly argued prose and van Wyhe himself has told me that the rules of fair play were suspended here, in that he was never granted a right to reply in Nature to the Odling-Smee piece. One particular problem is that Odling-Smee mis represents what van Wyhe did:

To carry out his study, Van Wyhe searched for the word "delay" in primary and secondary sources covering the period in which Darwin was working on Origin of Species.

In fact, this is a parody of what van Wyhe did. Rather than pursue such a simplistic approach, van Wyhe’s conclusions were built on over a year’s careful in-depth scholarship! And so far, no expert critique of van Wyhe’s paper has appeared in the academic literature, suggesting that his critics are short on counter-arguments.

So, I let me nail my colours to the mast and say that I think Dawkins has got it wrong here: there was no delay, no fear, no secrecy – nothing but perspiration racing to keep up with inspiration!



T Ryan Gregory said...

I enjoyed the post, and in general I agree. The point of my earlier post was simply that 1) people had been citing the essay without mentioning the fact that some other Darwin scholars do not agree with van Wyhe (the reason I cited Odling Smee is not the supposed search for a single keyword, but rather because it mentions other scholars who disagree and was the only source I knew of that made the point), and 2) that sometimes the fear of reaction leads to delay in a more complicated manner. As I concluded,

I think "yes or no" to the question of whether Darwin delayed publication out of fear is very simplistic. Anyone who has written anything of substance knows that sometimes the effect of fear of reaction is procrastination and/or excessive desire to include every piece of information available. Both can cause writing to take longer than it otherwise would. Was Darwin thorough? Yes. Is that one reason it took so long? Undoubtedly. Was he so thorough because of a fear of reaction? Probably at least in part.

Karen James said...

An excellent and well-researched post, Mark. I tend to agree with T Ryan Gregory's conclusion, i.e. that the delay was probably the result of a complex blend of factors, the sort with which anyone who's written a thesis or dissertation will be familiar.

I also wonder if a similar acknowledgement of complexity should be applied to Darwin's epiphany - he seemed to have bursts of understanding (his first sight of the mockingbirds and tortoises, the ruminating he did on the voyage home, the work with the pigeons, the moment in the carriage near Downe), each of which was an important step in the right direction.

Tim said...

You might be interested in this recent interview with Dawkins when he talks about the series, and Darwin's delay:


He mentions three possible reasons why Darwin might have chosen to delay publication, including the one you mention above. Why was only one reason mentioned in the series? I have no idea, but I suspect the director or editor might be a more likely suspect that Dawkins - there's only so much you can pack into three 45 minute slots after all.