On Natural Selection
First of all, the design of this volume is lovely. This is worth mentioning straight away, because I would not have bought it otherwise. I’ve been wanting to dip into Darwin for about a year now, but was worried about getting bogged down in The Origin of Species. I definitely made the right decision: reading Darwin, although not terribly difficult, isn’t something I could really see myself doing for 400 pages anytime soon. So this tidy, attractive volume served me well: at 117 pages, it was just the right amount of Darwin for a novice like me who is looking for a brief introduction to the actual thoughts and words of the great scientist — as opposed to the myths and controversies we usually encounter. Plus, the book felt great in my hand, and I enjoyed looking at it as I carried it around. (On Natural Selection is part of Penguin’s “Great Ideas” series, which includes two dozen compact, neatly designed versions of important works of nonfiction).
Darwin’s style is, for the most part, lucid, and even gripping at times. The steadfast confidence with which he sets forth his main theory is very endearing. It’s well-known that Darwin worked on The Origin of Species for years, and had been considering its main ideas for years before that, and was then finally forced to publish what he considered an abbreviated version of his theory in light of the fact that Alfred Russel Wallace was also arriving at the same conclusion. The sense of this is evident even in this abbreviated text, as Darwin seems loath to content himself with a single example to support his hypothesis, instead of the dozen he would prefer to give.
I was surprised to see that many of the most common objections to Darwin’s theory — at least the ones I’d heard — were actually covered by Darwin himelf in The Origin of Species. For example, intelligent design theorists like to use the human eye as an example of an “irreducibly complex” organ which could not originate by “chance” or nature. Darwin addresses this in Chapter VI (“Difficulties of the Theory”)
To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree. When it was first said that the sun stood still and the world turned round, the common sense of mankind declared the doctrine false; but the old saying of Vox populi, vox Dei, as every philosopher knows, cannot be trusted in science. Reason tells me, that if numerous gradations from a simple and imperfect eye to one complex and perfect can be shown to exist, each grade being useful to its possessor, as is certainly the case; if further, the eye ever varies and the variations be inherited, as is likewise certainly the case; and if such variations should be useful to any animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, should not be considered as subversive of the theory.
Basically, Darwin says: yes, I know it’s hard to believe — but given enough time, even an organ as complex as the human eye can arise from natural selection. Here’s a bit of his answer:
We must suppose each new state of the instrument to be multiplied by the million; each to be preserved until a better is produced, and then the old ones to be all destroyed. In living bodies, variation will cause the slight alteration, generation will multiply them almost infinitely, and natural selection will pick out with unerring skill each improvement. Let this process go on for millions of years; and during each year on millions of individuals of many kinds; and may we not believe that a living optical instrument might thus be formed as superior to one of glass, as the works of the Creator are to those of man?
These two selections are good examples of Darwin’s method, and demonstrate the level-headed reason that populates his text. It is remarkable that, given the radical nature of his postulation, Darwin is able to write with such confidence and keenness. His prose is the result of years of study, consideration, doubtfulness, and assurance. It’s quite stunning, actually.
I’d strongly recommend this book to anyone like me, who is looking to read Darwin’s original material, but wouldn’t know what to make of the entire Origin. I found that most of the lurking confusion I had about natural selection was allayed by this brief text, and now I find that I may, one day, want to read the entire Origin of Species after all.