Part-way through Darwin

I’ve been working my way slowly through Darwin, which is more an indication of the other pressures in my life than of the challenge of the book. Indeed, Origin of Species is a very pleasant, highly approachable work. Unlike Veblen, whose scorn for the world seems to manifest in part in unapproachable prose, Darwin is determined to make the reader comfortable on their journey, and never experience any disorientation.

The book itself seems to consist of a meticulous argument for evolution, with each chapter laying out the details for some aspect, and the next building upon that with more details. All of the examples that Darwin provides are straightforward and understandable, and many of them seem to be drawn from personal experience. For example, on the subject of selection, he talks about raising pigeons, and then expands on the different features prized by the pigeon fancier, and the process one goes through to select that as a breeder. With that under our belt, it’s easy to move to natural selection, where he can push the same principals forward in that context, often again referring to things he has seen with his own eyes.

The thing that comes through in reading Darwin that hadn’t ever quite stuck me before was the the essentialness of the struggle. Everyone knows survival of the fittest, but Darwin paints a picture of struggle at such a large and perpetual scale, that only now are the mechanics of evolution becoming lucid to me.

And in the last section I read, he hit upon a topic I’ve always wondered about: extinction. There have been different efforts in recent decades to save this or that species from extinction, and I’ve always privately asked myself, why? If survival of the fittest is how the world works, and a particular species is on the way out, why should I care. Makes me feel like a heartless grouch, so I was gratified to find Darwin on my side in this argument:

Nevertheless, so profound is our ignorance, and so high our presumption, that we marvel when we  hear of the extinction of an organic being; and as we do not see the cause, we invoke cataclysms to  desolate the world, or invent laws on the duration of the forms of life!

Profound ignorance, indeed.

He goes on to tell a little story about the interrelationship between all things, which is so charming and persuasive I have to include the whole thing here. This is survival of the fittest.

I am tempted to give one more instance showing how plants and animals, remote in the scale of nature, are bound together by a web of complex relations. I shall hereafter have occasion to show that the exotic Lobelia fulgens is never visited in my garden by insects, and consequently, from its peculiar structure, never sets a seed. Nearly all our orchidaceous plants absolutely require the visits of insects to remove their pollen-masses and thus to fertilise them. I find from experiments that humble-bees are almost indispensable to the fertilisation of the heartsease (Viola tricolor), for other bees do not visit this flower. I have also found that the visits of bees are necessary for the fertilisation of some kinds of clover; for instance twenty heads of Dutch clover (Trifolium repens) yielded 2,290 seeds, but twenty other heads, protected from bees, produced not one. Again, 100 heads of red clover (T. pratense) produced 2,700 seeds, but the same number of protected heads produced not a single seed. Humble bees alone visit red clover, as other bees cannot reach the nectar. It has been suggested that moths may fertilise the clovers; but I doubt whether they could do so in the case of the red clover, from their weight not being sufficient to depress the wing petals. Hence we may infer as highly probable that, if the whole genus of humble-bees became extinct or very rare in England, the heartsease and red clover would become very rare, or wholly disappear. The number of humble-bees in any district depends in a great measure upon the number of field-mice, which destroy their combs and nests; and Colonel Newman, who has long attended to the habits of humble-bees, believes that “more than two-thirds of them are thus destroyed all over England.” Now the number of mice is largely dependent, as every one knows, on the number of cats; and Colonel Newman says, “Near villages and small towns I have found the nests of humble-bees more numerous than elsewhere, which I attribute to the number of cats that destroy the mice.” Hence it is quite credible that the presence of a feline animal in large numbers in a district might determine, through the intervention first of mice and then of bees, the frequency of certain flowers in that district!

 

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