A Pleasant Evening with Charles

I was reading through The Origin of Species last night, and Darwin surprised me. Unlike many caught up in the debate on evolution, Darwin was by no means acerbic or polemic in his arguments. At least from The Origin of Species, I get the impression that were he alive today, he would be a genuinely nice guy who would want to engage in a real, substantial debate about his theory. For instance, in his conclusion (ch. 14) he says,

That many and grave objections may be advanced against the theory of descent with modification through natural selection, I do not deny. I have endeavoured to give to them their full force.

While he does not find objections ultimately valid, he at least does not dismiss them out of hand.

As a whole, though, I found a few things lacking with his argument. For one, consider the following, also from chapter 14.

It is, no doubt, extremely difficult even to conjecture by what gradations many structures have been perfected, more especially amongst broken and failing groups of organic beings; but we see so many strange gradations in nature, as is proclaimed by the canon, `Natura non facit saltum [Nature makes no leap],' that we ought to be extremely cautious in saying that any organ or instinct, or any whole being, could not have arrived at its present state by many graduated steps.

This seems to be a summation of his logic, which can be expressed in the following manner: We cannot rule out the possibility that natural selection did not cause the evolution of all species from one or a few species, so therefore this is what happened. In other words, Darwin has turned the table. Before him, the basic assumption was divine creation. After him, it becomes natural selection. The logic underpinning his view, however, is extremely weak, and it is my guess that it came about due to his views on God and the problem of evil.

Second, he does not account for the origin of the originator of species. For instance:

I believe that animals have descended from at most only four or five progenitors, and plants from an equal or lesser number. Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype. But analogy may be a deceitful guide. Nevertheless all living things have much in common, in their chemical composition, their germinal vesicles, their cellular structure, and their laws of growth and reproduction…Therefore I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed.

With his theory, he can trace back all life to roughly ten progenitors. He hypothesizes that those ten, in turn, likely descended from a single ancestor, though unlike his previous logic, he is quick to point out that this argument is also very weak. Example two (from ch. 6):

How a nerve comes to be sensitive to light, hardly concerns us more than how life itself first originated…

Here he is talking about the evolution of the eye, which was one of the main arguments against him at the time. But notice something from these two examples: He cannot and does not even want to account for the origin of life itself. (Notice, however, his metaphor of "breathing life into" the first being, which is an ironic reference to the Creation story of Genesis.) He is happy to leave his theory where it is--common descent from one or a few life forms whose very existence is not important to explain.

Darwinism has come a long way since 1859, perhaps going further than Darwin himself would have wanted. Yet no Darwinist will seriously challenge the weak logical foundation of the theory (it might have happened, so it did). Also, after 150 years, no one has been able to put a satisfactory answer to the origin of life, an answer that is very important but Darwin saw no use for in his book.

Ultimately, I think if Darwin could see the blind dogmatism and extremism that can happen on both sides of his theory, he would shake his head and wonder what happened.

(I apologize for not having page numbers for The Origin of Species references. I don't have access to the book right now; I had to rely on an e-copy.)