Philosophy 167: Class 9 - Part 12 - A Modern Example of a Similar Science: Darwin's Theory of Heredity and Evolution.
Smith, George E. (George Edwin), 1938-
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Now I forewarned Patrick of this so he can also just say, I don't want to talk about this. I'm being unfair to him. But I looked at what Decartes did and the extent to which he took a group of phenomenon and constructed an explanation based on details of mechanism that are totally wrong, and I thought, this has a lot in common with Darwin.
Darwin's theory of heredity was totally wrong. He had no real basis. He didn't look at all, at not just the possibility of drift, but how large a mating population has to be for any mild fitness pressure to become fixed. All of those things happened in the 20th century.
They all saw it as questions given rise to by Darwin. But what Origin of Species had put forward is a possible story. It's a wonderful story for two reasons. Now my view, and Pat knows. Pat's forgotten more about Origin of Species than I'll ever know. Number one, they had discovered in the generations before, one or two generations before, there are just a god-awful lot of species that had existed on the Earth and had gone extinct.
And that really bothered people, particularly the religious people. There's a whole series of treatises called the Bridgewater treatises, trying to reconcile religion with the state of science from the first half of the 19th century, okay? And Darwin knew all of it, he knew, I think all of the people who wrote those treatises as well as the treatises themselves, and here was a response to that and it was totally naturalistic.
There was need for an external intervention. But it is still very much an explanatory scheme or am I wrong about that? Patrick, it comes to you. You didn't have to raise your hand, I was leading to you.
So a few things to say. So there is an explanatory scheme to propose, and then he does have some bold conjectures.
And so I see the comparison, but I think that overall the analogy to Descartes sells Darwin awfully short for two primary reasons. So the first is that there's a difference in, sort of, strategy here, whereas Descartes' were boldly speculative. And he has sort of arguments and motivations for being boldly speculative to avoid the Ptolemaic mistakes so to speak as you just put it.
Darwin isn't that way at all. He's sort of spent decades doing detailed naturalism before he started to formulate the theory of evolution. The second point is that when he proposes the theory of evolution and the origin of species, this sort of two main components in there are the tree of life hypothesis and evolution by natural selection.
And the tree of life hypothesis is so meticulously supported by data and does such a wonderful job unifying a disparate phenomenon, it's almost immediately acceptable. Natural selection was much more controversial.
And that's of course a part.
And to steal your he himself called it his mad dream.
But that wasn't actually in so I think, so what's in this course the person of all the analogies used are imperfect. But the person I think might be the best analogy
I think that might be Wallace.
Yes because of Lincoln's careful attention to very precise experimental set ups.
And he sort of eschewed Gray and theorizing the way Descartes did right, and that was sort of Darwin's, so if you look back in his history on the orchids and all the work he was doing leading up to the orchid lays this beautiful foundation of data. So he's already turned a lot of data into evidence I think.
And the Origin's just the whole proclamation of this theory he spent decades cultivating.
But the explanatory scheme of natural selection itself comes closer to this.
That I think is the best, yeah, so I think that's the best analogy because
It is for boldly explanatory, boldly speculative, but even so the way Darwin goes about it, goes back to strategy.
The way he goes about proposing natural selection is by this sort of very careful analogy to sort of human driven artificial breeding.
Well that's what I was going to bring up. He knew what they had done to dogs. In between 1830 and 1850, most of our breeds were created by breeders in England at the time.
Dogs, horses, pigeons, right, and what's kind of amazing about that is he pulled basically Lyle's move, right? Let's look at horses that are operating now in this small window of time and scale it up over millions of years. This is kind of neat uniformitarian move. There was already precedent for that, as geology's taken off by the time Origin is written, Lyle's a close personal friend and mentor to Darwin.
So there's that kind of move there and I don't see Simpson doing something similar with Descartes. He had this sort of vortex used to unify cosmology felt that he needed to unify cosmology. But he seems like he's on shakier ground.
It's funny that you know he did a huge amount of dissection of animals as Descartes did, and humans.
No, no I'm just pointing out there's no way to do this outside in and how to do fluid experiments in fluids. They're very hard to do.
I agree and as you mentioned we still don't have good theories of the mechanics of fluid dynamics.
Not as much as we would like to have.
Well, and for those that don't understand this, we have an equation that we think applies to virtually all fluid phenomenon of reasonable scale, the Navier-Stokes equation. It's one of the million dollar, or whatever the number is, $10 million prizes to be able to solve it. The equation's intractable.
So if that's the situation where.
But the idea that an explanatory driven science is not science doesn't look right from a Darwinian point there.
I think that's right, and even, you know, today, with the mathemetization of evolutionary theory that happened in the 20th century population shift.
That resembles more of what's going on with Descartes than what Darwin did, because there you've got these very simple mathematical models that don't match up with what's actually happening, because what's actually happening is so complex.
But in a way they also resemble Galileo because they are so simplified in their relation to the actual world as an open question.
And they are very mathematical.
At any rate, I'm happy if you just walk out of this. Firstly, you can read Shuester on why we should take this science. But I'm happy if you see it, and we shouldn't just dismiss it as a philosopher making a fool of himself trying to do science.
That's what they thought of Newton, as a mathematician making a fool out of himself trying to do science in the Principia. So that picture, there's a right way to do science, and this is it. This is what Newton didn't do. That's why he was making a fool of himself.
He wasn't providing all the mechanisms by which gravity works. So, I'm happy though, if you simply make the adjustment that this can be viewed as a sensible empirical strategy, maybe not the best. But a sensible empirical strategy and the piecemeal work instead of a broader picture can be very dangerous, can be very very misleading.
In fact, how to prevent it from being misleading is probably one of the central questions of economics as a discipline.