Darwin Wasn't Wrong (well, maybe a little)

Back in January, New Scientist magazine published an issue with a featured cover article that boldly proclaimed "Darwin was wrong".

The article itself was a fairly comprehensive round-up of recent (the last few decades) research into the state of the so-called "tree of life" - an idea of Darwin's that evolution could be modelled using a tree metaphor: that life begins with a single trunk (a last, common ancestor to which everything is related) and proceeds through time, branching at speciation events and eventually ending on the tips of the branches - the modern, extant species.

Like so many simple ideas, the tree of life metaphor has subsequently been tweaked and honed to include discoveries such as horizontal gene transfer (HGT - the idea that genes can be passed horizontally between species, as well as vertically through reproduction) and endosymbiosis (the absorption of members of one species by members of another, to produce a single entity). In fact, the tree metaphor in the world of microbes is better seen as a net or a mesh, in which information is routinely passed between entities, a constant criss-crossing of lines, more chaotic and less ordered than we'd previously supposed.

What's less contentious is the applicability of the tree metaphor to multicellular animals - plants, birds, fish, humans, the big stuff. It's true that HGT seems to have a place in this part of the animal kingdom, mostly through viral interaction, but the overwhelming process of information transfer is vertical through reproduction and the tree of life idea is still valid. The article states:

Nobody is arguing - yet - that the tree concept has outlived its usefulness in animals and plants. While vertical descent is no longer the only game in town, it is still the best way of explaining how multicellular organisms are related to one another - a tree of 51 per cent, maybe. In that respect, Darwin's vision has triumphed: he knew nothing of micro-organisms and built his theory on the plants and animals he could see around him.

Darwin wasn't wrong as such, he just didn't know everything. In many ways, he was "wrong" in the same way that Newton was wrong about motion - relativity just provides a correction in extreme cases, the non-relativistic cases that Newton proposed are still applicable in everyday use. And so it's the same with Darwin's tree: it is still extremely useful in explaining the nested hierarchies seen in the animal kingdom.

So what's the problem? The issue is that boiling down this discussion to a simple "Darwin was wrong" is extremely suggestive, and biological evolution is one field where every word is scrutinised and mangled to provide ammunition in an ongoing "culture war". Putting "Darwin was wrong" in large type on the front cover of one of the world's leading popular science journals is simply irresponsible and ill-considered. There is no doubt in my mind that most people reading that headline would immediately see "Evolution" in place of "Darwin", and that changes the impact of the cover significantly.

In fact, New Scientist even foresaw this possibility. This is from the editorial that accompanied the article:

As we celebrate the 200th anniversary of Darwin's birth, we await a third revolution that will see biology changed and strengthened. None of this should give succour to creationists, whose blinkered universe is doubtless already buzzing with the news that "New Scientist has announced Darwin was wrong". Expect to find excerpts ripped out of context and presented as evidence that biologists are deserting the theory of evolution en masse. They are not.

If they saw the damage that could be done, then why on earth did they go ahead with publishing it? You can't help but conclude that this was a cynical attempt by the publishers to increase volume of sales by generating false-controversy.

And what has the impact been? Reassuringly, most of the noise has come from science bloggers, keen to scald New Scientist for the cover. But already there are reports of the cover image showing up in creationist presentations, unsuprisingly accompied by no meaningful content from the actual article. And, of course, the ever-reliable Uncommon Descent has been quick to jump on this as another example of the ongoing demise of materialist science - neglecting to mention that HGT has been known about for decades.

Ultimately, this is a tricky one. On the one hand, scientists have to be very careful of any undue veneration. Darwin should not be free from valid criticism. He is no more the Messiah of Science that creationists paint him to be than Newton, or Gallileo, and his ideas should be as much subject to scrutiny as anyone's. On the other hand, great care must be taken to ensure that science reporting is not sensationalistic and provides no ammunition to an increasingly resurgent and powerful creationist lobby - a movement that has proven time and again that out-of-context quote-mining is a tactic that is more than willing to deploy.