Finalmente um evolucionista com os pés nas evidências, oops no chão

terça-feira, novembro 24, 2009


It was 150 years ago tomorrow


… Sergeant Pepper… oops, sorry, wrong theme.

150 years ago tomorrow, people suddenly became smart, observant and able to understand the world. Right? Right?

Well, look, I have enormous respect for Darwin, and I think the Origin is a cool and interesting book, but really, no. People were working on understanding the world before Darwin, and in fact Darwin saw what he was doing as very much in the same mould as his scientific mentors and heroes. His ideas have turned out to be, if not quite right, then productive and useful in the progress of science, but measured carefully, Darwin’s theories and ours are not really the same, if you are thinking of the content.

Let us by all means celebrate the man and his achievements. But let us not make him into a demigod, either (nor any scientific hero – if Pasteur discarded 90% of his data, and he did, that doesn’t belittle his contributions to science, and if Mendel made his data fit his model, and he probably didn’t but might have, that doesn’t change one whit the facts of genetics as we now understand them). Darwin did not invent the ball point pen, antibiotics, the iPhone (all hail the Prophet Jobs!), or BLTs, either. What he did is what he did, and more power to him.


What we need to know is that Darwin founded not a theory, or even a set of doctrines, but instead he is the focal point of a series of traditions that converged in his ideas and writings, and which have derived from him. He did not invent biogeography; de Candolle is a good candidate for that. He did not invent natural selection, although he was perhaps the first to think of it as an agent for evolutionary change (excepting Patrick Mathew, who buried his light under a naval architectural bushel). He did not invent genetics (although the term gene comes from his notion of a pangene, and he probably set many people thinking about heredity in a serious manner). He did not give us a mathematical theory; that was William Castle, JBS Haldane, RA Fisher and Sewall Wright, among others to this day.

The Origin acted as a seed in a supersaturated cultural solution. The solution was already set to crystalise, and he came along and made evolution, phylogeny, heredity, dispersal, and other topics respectable. So far from being a “class traitor” as Desmond and Moore make him out to be, Darwin’s bourgeois respectability is what made him effective as a motivator of evolutionary biology, where evolution had previously been seen as politics in naturalists’ dress. He was in many ways more prescient than those who followed him. But had he not lived, had he drowned on the Beagle voyage, as Peter Bowler is presently writing a what-if history, would we have had evolution anyway? Almost certainly. If Owen hadn’t shaken off the shackles of the clergy who ran Cambridge, very likely others would have. But the tenor of the field would have been somewhat different. Here’s how I think it would have played out, based on a discussion with Bowler about his work. Anything original is his.

Common descent/phylogeny might not have developed as early. Heinrich Bronn had given an “evolutionary tree” in 1858, but his mechanism was no different to Buffon’s – the degeneration of types from an original stock; basically evolution was localised and played out on existing potentialities.

Natural selection might not have been seen to be a mechanism of evolution for another fifty years, and when it was, it would not have been in terms of an analogy with artificial selection. Wallace would have been “rediscovered” the way Mendel was, without being all that influential directly. Sexual selection might not have popped up until the mid-20th century or so.

There would have been a much stronger emphasis on developmental biology, coming out of von Baer’s work and later experimental developmental biology in Germany. Evo-devo would have been the first state of the field. Would this have had more experimental support? I doubt it. People tried very hard to get experimental evidence before the synthesis, but were hampered by a set of questions that could not be answered within the existing techniques. The same thing would have been true, I think of developmental biology.

Lamarckism, by which I mean the progressivist view of evolution, not the “acquired inheritance” version that has little to do directly with Lamarck and anyway is set up as a contrast with Weismann not Darwin, would have played an even greater role in people’s thinking than it did. It may still be with us now – we would be trying to figure out how progress occurs out of necessity, rather than it being the rather odd view of people like Conway Morris.

One thing that I seriously doubt, under this scenario, is that it would be seen as a challenge to religion. The reason why Darwin was seen as a modern Epicurus is because he allowed for a creative role for chance. This is a red rag to a bull to theists. Chance is always seen by them as the elimination of order, not as a way to generate it. By the time people discovered that it could be, most likely out of physics (if Boltzmann was not influenced by Darwin, would we still have thermodynamics in the same way? Another what-if), the threat would be seen as coming from that quarter and not evolution.

So, no creationism. Probably no great angst about teleology from the Christian churches – one thing that people were seriously threatened by was the Darwinian idea that teleology or purpose was not needed any more to explain purposiveness in “organised beings”, i.e., living things. Again, that probably would have come out of physics.

And there still would have been the Holocaust, unless historical contingency prevented antisemitism from taking political power in Europe, which I doubt. There still would have been a communist movement – that was well advanced before Darwin came along.

It’s fun to speculate on a world without Darwin, but since there was a Darwin and he did write the Origin, let us celebrate him, for what he was, and not for what he wasn’t.

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Source/Fonte.

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NOTA IMPERTINENTE DESTE BLOGGER:

Ainda existem darwinistas realistas e lúcidos da realidade da importância de Darwin, mas com os pés nas evidências, oops, no chão!