A good rule of thumb in my reading is that I can’t go wrong with a Richard Dawkins book. So I picked up this 1996 one, Climbing Mount Improbable.
The title is a nod to the workings of evolution by natural selection. Its results may indeed seem improbable, something that has always confuzzled doubters and “intelligent design” advocates. Unable to accept that the Nature we see in all its complexity could have emerged without some conscious force. Yet when it comes to hypothesizing that force, their skepticism vanishes, swallowing what’s truly a far greater improbability.
Another key common mistake is to think the alternative to design is species arising by random chance, as if that’s what Darwinism means. Not so. As Dawkins stresses, it’s very much a non-random process — “which creates an almost perfect illusion of design.”
There’s a long discussion of spiders and their webs. Spiders must solve a large array of problems and challenges to make the system work. They do it through compromises, and what, in computer lingo, would be called kludges — inelegant solutions that do get the job done. For example, how to start building a web in the first place is far from simple. Turns out some spiders use what amounts to a scaffolding, taken down once the actual web is done. Another problem is to avoid getting stuck in your own web. The solution is pretty complicated, but spiders, with their high IQs, have figured it out.
That’s facetious of course. Their behaviors are just encoded in their genes. No thinking (as we think of it) is involved. So how did they get those genes? Natural selection. Each spider gets its parents’ genes — but not quite exactly. Mutations cause slight variations. Perhaps making certain spiders a bit better at web building. Hence more likely to produce offspring. Multiply that over zillions of generations, and the resulting standard spider can be a lot better at web building. Mutations are matters of chance, but their results are not. That’s natural selection. No designer needed.
But — why are there spiders at all?
It does seem a kind of crazy Rube Goldberg way to get food. Why not just prey on critters smaller and/or slower? Of course, plenty of animals do exactly that. So again, why does Nature need spiders?
Well, creatures do not evolve to fill some sort of need. Instead, natural selection might be seen as quintessentially opportunistic. Nobody “thought up” the idea of an insect using a web to catch food. Rather, the first proto-spiders that happened to make primitive web-like things — quite possibly for reasons other than feeding — turned out to have some at least marginal reproductive advantage. Then it’s off to the races.
Still, one could think of many alternatives. Like, why not build a cage, maybe even bait it with some ersatz lure? (Which actually some flowers do.) Would that be any more improbable than spider webs?
But Nature doesn’t think up ideas. Instead it works with what it’s got. That indeed is why so much of Nature, rather than reflecting “intelligent design,” is a mess of kludges.
Take our own anatomy. There’s some bad plumbing design in our throats, with air and food sharing a passageway, resulting in frequent choking. An intelligent designer would never have done that.
But we’re stuck with it because we evolved through piecemeal modification of ancestors all the way back to fish and even earlier life forms. And having a third eye in the back would be ever so useful. But that was never possible because our anatomical heritage couldn’t allow for it.
Then how about penises? I mean the location. Could it be, like, more awkward? For all animals — intercourse looks like contortions. The design does work, but not really that well.
Anyhow, as Dawkins explains, Darwin skeptics don’t see how the Mount Improbable of a creature’s immense complexity could be ascended in a single leap. But Nature needn’t do that. Instead Dawkins has it going ’round the mountain’s rear and slowly reaching the top via a long gentle slope.
A key concept in evolution is found in Dawkins’s invoking the guy who asked directions to Dublin and was told, “Well, I wouldn’t start from here.” The point again being that evolution starts where it starts, not where it chooses. Take whales, and other sea mammals. They, like all mammals, started way back as fish, breathing through gills; then became terrestrial and developed lungs; then later re-submerged. Now requiring frequent surfacing to get air. Why not re-evolve gills? Vestigial gills do still show up in their embryonic development.
But meantime, Dawkins explains, their entire anatomy had been reconfigured for lung breathing, so to reinstate gills would require a total remodeling. Not impossible, but it would mean going through a kludgy transitional phase working less well than either mode. Equivalent, Dawkins says, to traversing a deep valley between two mountain peaks in order to climb the higher one eventually. But evolution does not “allow for getting temporarily worse in quest of a long-term goal.” And remember that “temporarily” would actually be many generations of sub-par adaptation. They’d die out before reaching the second mountain.
Meantime, is getting oxygen through gills an optimal system even for fish? Here again an “intelligent designer” might have come up with a better one. While whales, had they originally been designed for the sea, would be very different — more like fish!
Creationist doubters of evolution are always jeering about “missing links.” If one species becomes another by evolution, why do we find no intermediate forms? Dawkins explains that this disregards how scientific classification works. Every species entails some variability; nevertheless, every biologic specimen or fossil is assigned to a particular species, based on which it’s most like. In that schema there are no “in-betweeners.” So the idea of “missing links” is simply wrong. Moreover, a species’ fossil record often actually does show gradual evolution through intermediate forms. The horse is a good example, evolving from a quite small ancestor, through a series of larger ones, into the animal we know today.
Our discovery of Darwinian natural selection is a great landmark in our own evolution, from a lower form to a higher form of knowledge.