Dawkins: Climbing Mount Improbable
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Richard Dawkins, Climbing Mount Improbable. New York : W.W.Norton & Company, 1996. xii + 340 pages, with bibliography and index; illustrated, original drawings by Lalla Ward.
"Mount Improbable" is a metaphor. Since the birth of natural selection, it has been seen as a challenge (rightly or wrongly) for Darwin's idea to explain convincingly how complicated creatures like humans could have arisen through evolution from simpler creatures. It is often erroneously thought that genetic mutations that led to, say, the creation of the eye are too improbable to have occurred. Dawkins uses his metaphor of the mountain to explain how evolution scales the side of Mount Improbable just one step at a time, so that reaching improbable heights are seen as possible—and understandable.
It's a fine idea, and he discusses many interesting cases of complicated animal systems in fascinating depth: wings, eyes (of which is seems natural selection has separately evolved some 40 different models), symbiotic wasps and figs, spiders and their webs, the shells of snails and mollusks.
All in all it should have been more compelling reading than I found it. The topics are interesting, they are great examples of "climbing mount improbable", and Dawkins writes with animation and enthusiasm. Still, for me, something was missing, and it's hard to put my finger on just what it is. It goes beyond his poor use of the Mount-Improbable metaphor.
In a way, I think Dawkins writes too slowly for my taste: I get impatient for him just to get on with it. He also seems to emphasize those ideas that I don't think need emphasis and gloss over those bits where I want to linger. I'm coming to suspect that I'm not his ideal audience.
As I complained about in his The Blind Watchmaker, he introduces in this book a couple of computer models, one for the evolution of spider webs, one to describe shell shapes, and he seems exceptionally enamored of them. Dawkins and I evidently see differing amounts of insight about reality in his computer models. We would agree that models and simulations can give insight into natural processes, not by modeling reality with great fidelity but by capturing some essential characteristic of a real process and elucidating that process. He finds that his models capture more essence than I think they do. He also seems charmed by incidentals of the computer and spends too many words describing in detail those things that really don't contribute to understanding the point of the simulations.
At the beginning of the book Dawkins spends a great deal of time trying to develop a very precise idea of just what an "objective" definition of "design" might be. He wrote this before the more recent troubles here in the US with so-called "intelligent design", but his argument is directed at those who all too readily see the hand of a designer where natural selection will do. I thought he belabored the point; others might rejoice at his careful attention.
At least his writing is not dull and, generally speaking, he has interesting science to talk about. Here he takes the opportunity to illustrate how natural selection works with available material, at the same time clear up a mild misunderstanding about evolution in moths.
For instance, my Oxford colleague the late Bernard Kettlewell famously studied the evolution of dark, almost black, moths in species that had hitherto been light-coloured. In the species he especially studied, Biston betularia, dark individuals tend to be slightly hardier than light ones, but in unpolluted country districts they are rare because they are conspicuous to birds and are promptly picked off. In industrial areas where tree trunks have been blackened by pollution, they are less conspicuous than the light-coloured forms and consequently less likely to be eaten. This also allows them to enjoy the additional advantage of their natural hardiness. The consequent increase in numbers of dark forms, to overwhelming numerical dominance in industrial areas since the mid-nineteenth century, has been dramatic and is one of the best attested examples of natural selection in action. And no we come to the reason for introducing the case here. It is often wrongly thought that after the Industrial Revolution natural selection worked on a single brand-new mutation.. On the contrary, we can be sure that there have always been dark individuals—they just haven't lasted very long. Like most mutations, this one will have been recurrent but the dark moths were always rapidly snapped up by birds. When conditions changed after the Industrial Revolution, natural selection found a ready-made minority of dark genes in the gene pool to work on. [pp. 87—88]
From later in the book, here's a nice bit of history about notions of design and how difficult they can be to set aside.
I was driving through the English countryside with my daughter Juliet, then aged six, and she pointed out some flowers by the wayside. I asked her what she thought wildflowers were for. She gave a rather thoughtful answer: "Two things," she said. "To make the world pretty, and to help the bees make honey for us." I was touched by this and sorry I had to tell her that it wasn't true.
My little girl's answer was not too different from the one that most adults, throughout history, would have given. It has long been widely believed that brute creation is here for our benefit. The first chapter of Genesis is explicit. Man has 'dominion' over all living things, and the animals and plants are there for our delight and our use. As the historian Sir Keith Thomas documents in his Man and the Natural World, this attitude pervaded medieval Christendom and it persists to this day. In the nineteenth century, the Reverend William Kirby thought that the louse was an indispensable incentive to cleanliness. Savage beasts, according to the Elizabethan bishop James Pilkington, fostered human courage and provided useful training for war. Horseflies, for an eighteenth-century writer, were created so 'that men should exercise their wits and industry to guard themselves against them'. Lobsters were furnished with hand shells so that, before eating them, we could benefit from the improving exercise of cracking their claws. Another pious medieval writer thought that weeds were there to benefit us: it is good for our spirit to have to work hard pulling them up. [pp. 256—257]
The notion that he discusses, that all was created for our benefit by a benevolent God and that evidence of God's hand is everywhere if we will only look, is alive and well today, at least in the US. In evidence he offers this from a creationist tract he received:
Note that the banana:
- Is shaped for human hand
- Has non-slip surface
- Has outward indicators of inward contents: Green—too early; Yellow—just right; Black—too late
- Has a tab for removal of wrapper
- Is perforated on wrapper
- Biodegradable wrapper
- Is shaped for mouth
- Has a point at top for ease of entry
- Is pleasing to taste buds
- Is curved towards the face to make eating process easy. [p. 258]
No one says that talking about science can't be fun.
Sometimes when I read Dawkins I feel as though he's arguing enthusiastically and thoughtfully for all the right ideas but that his arguments don't always thrust in exactly the right direction. It seems that he and I are on very similar but slightly different wavelengths.
However, we can find substantial agreement on a philosophy of sharing science with others, as he puts forth here.
I should like to thank Charles Simony, not only for his immense generosity in endowing the post in Public Understanding of Science which I now hold at Oxford, but also for articulating his vision—which coincides with mine—of the craft of explaining science to a large audience. Do not talk down. Try to inspire everybody with the poetry of science and make your explanations as easy as honesty allows, but at the same time do not neglect the difficult. Put extra effort into explaining to those readers prepared to put matching effort into understanding. [p. x]
Climbing Mount Improbable isn't his strongest book. Given a choice of just one Dawkins book, I'd still go with The Ancestor's Tale.
-- Notes by JNS