Mr Darwin's new science

In his recent, marvelous must-read book, Naturalists in Paradise, about the major explorers of the Amazon (Wallace, Bates, and Spruce), John Hemming quotes Alfred Wallace lauding Darwin’s Origin of Species in a letter to fellow explorer Henry Bates, saying that “Mr. Darwin has created a new science and a new philosophy.”

I am no historian of science by any means, but I think that there is substance in this grand characterization.  Prior to Darwin–taking him as representative and perhaps the most explicit spokesperson for the view–western science had viewed life as the result of one or more divine creation events.  The inanimate, physical universe was also created ‘In the beginning’, but as a law-like place.  At least, by Galileo and Newton and others, it had come formally to be seen as following universal mathematical principles.  The key, in my view, is the ‘universal’ aspect of this view of existence.

Later, with various scientists leading up to them, Darwin, Wallace and a few others saw life itself as also having arisen at some ‘beginning’, but a natural one, and as a process, having diversified thereafter to what is here today.  That process has come to be called evolution.  The idea from Darwin’s time to now, with no evidence of serious challenge, as he said, all life today has descended from some beginning in ‘a few forms or into one’ following universal ‘laws acting all around us’.  In asserting his view, in terms of laws, Darwin reflected his essentially explicit Newtonian viewpoint.

These ‘laws’ were, as specified by Darwin in the elegant last paragraph in his Origin of Species:

1. Growth with Reproduction
2. Inheritance
3. Variability ‘from the indirect and direct action of the external conditions of life, and from use and disuse’
4. Resource-limited rates of increase leading to a struggle for life
5. Natural Selection, which led to divergence of Character and Extinction of less improved forms.

I often note my view that Darwin was a product of his times, that is, believing in ‘laws’ of Nature and a kind of determinism in evolution, and a poor sense of probabilism.  As I note in some recent posts, I think he held this view, expressed clearly in terms of barnacles, but I wonder what he would have said about primates and humans in particular, as recently mused about here.

We’re now in the world of probabilism in science, with fundamental probabilistic notions (mutation, drift, quantum mechanics, and so on).  Darwin would certainly have understood the ideas, but I wonder what his view of the probabilistic aspects would be.  That they were just a nuisance on the ‘real’ selective signal?  That they challenged the idea of precise adaptation?  How would they have affected his analysis of barnacles, as we’ve discussed recently here?

But is evolution law-like the way physics is?  Physics’ ‘laws’ are universals.  Yet evolution (including selection) happens probabilistically, in the context of specific local circumstances.  This seems at odds with Newtonian universality and its consequent determinism.  Is anything missing in our ‘theory’ of life and evolution, for example, that vitiates promises of ‘precision’ genomic medicine?  Or that could be used to derive such predictability?  Or is it just that such promises are Newtonian, and don’t fit the evolutionary living world in which we live?

Mr Darwin (and some contemporaries, in particular Alfred Wallace) founded a new science, but we have to go beyond his times to understand where that science will, or should, take us.