Hat And Beard 1 – Chuck D

As you probably know, today is the 200th anniversary of the birth of two of the greatest people who ever lived, Abraham Lincoln and Charles Darwin, and given that I write here about politics and science it seemed absurd not to mark this (those waiting for the last Final Crisis post will have to wait a bit more – I was going to post yesterday but my home net access was FUBAR, and I’m writing these two today. But I’ll have a very long, special post for you on Saturday). For Lanky Linc I’m just going to talk about freedom generally, rather than Lincoln’s own achievements specifically (though I’m sure this will disappoint my friend Tilt, the one person I know who has a recording of the Gettysburg Address on his MP3 player) as I think everyone reading this will be broadly in agreement that slavery was a bad thing. However, it is likely that people reading this will *not* know some things about Darwin that are worth knowing, so here’s a rough guide to some misconceptions about Darwin, and to what he *actually* did:

Misconception 1 – Darwin came up with the idea of evolution
As a matter of fact, the idea of evolution had been current in biology long before Darwin, starting with Jean-Baptiste Lamarck, and supported by such notable biologists of the time as Buffon and Darwin’s grandfather, Erasmus Darwin. However, the reason Lamarck is considered to have been mistaken and Buffon and Erasmus Darwin’s names now survive only as footnotes to literature of the time (Buffon mentioned as being current in Shaw’s boyhood in the Lamarckian preface to Back To Methuselah and Erasmus Darwin’s experiments with vermicelli being an inspiration for Frankenstein) is that they hadn’t come up with a satisfactory explanation of how or why evolution happens, ‘just’ observed that it did. Their best guess (and it was a reasonable one) was that, for example, a proto-giraffe wanted to reach higher leaves, so stretched its neck out until it could, then passed that stretchy neck on to its descendants. This idea, of evolution having a purpose or being directed by a mind toward a goal, still seems very popular among the public (it resurfaces, for example in Terry Nation’s Dalek stories and Grant Morrison’s X-Men run) but it’s almost universally regarded as wrong by the scientific community (except for a couple of people on the margins like Rupert Sheldrake, who is also almost universally regarded as wrong by the scientific community).

What Darwin came up with was the idea of natural selection.

Darwin’s work had something to do with genes
While genetics provides a lot of modern support for Darwin’s ideas, and a lot of popularisers like Richard Dawkins now explain his ideas in those terms, the science of genetics developed later than evolutionary biology, and to start with relatively independently. The ideas in genetics were originally the work of the Austrian monk Gregor Mendel, and the molecular basis of modern genetics was mostly worked out by Rosalind Franklin based on earlier work by Linus Pauling (then Crick & Watson put the finishing touches on Franklin’s work and took the credit for themselves). Genetics and evolutionary theory reinforce each other, but they developed independently.

Evolution is ‘just a theory’, it’s not been proved
This is literally true, but it’s also a misunderstanding of how science works. Contrary to media reports, there is no such thing as ‘scientific proof’ and nothing has ever been ‘proved’ scientifically – everything in science is contingent, and subject to change if new evidence comes in. That, more than anything else, is what makes science science.
However, the word ‘theory’ has a rather more technical meaning in science than it does in vernacular English. When speaking casually, we can say “I have a theory about that…” meaning just “I have an idea”. In science, on the other hand, that would be called a conjecture or (at best) a hypothesis. A theory is an idea which explains things that have been observed, that contains testable predictions, and that has been tested multiple times and found to be correct every time. It could still be wrong, but once something’s called a theory it’s extremely unlikely to be wrong, because it agrees with every test we can put it to. The mass of evidence for the idea of evolution is large enough that we can safely say we’re as sure that evolution happens as we are of anything. We might still improve some of the fine details, just as happens with the theory of (say) gravity, but just as we know that if we drop a heavy weight it’ll fall, even if we turn out to be wrong about the twentieth digit of the gravitational constant, we know that humanity came from an apelike ancestor which came from a monkeylike ancestor which came from a shrewlike ancestor and so on.

So what did Darwin do? Well, two things.

Firstly, and least importantly, he provided a greater mass of evidence for the idea of evolution than anyone had ever done before, and all in one place. On The Origin Of The Species is a great book, but it’s also almost unreadable, and for much the same reasons as those other two great unreadable books of the 19th century Capital and The Golden Bough – the sheer, unrelenting mass of detailed evidence he provides is enough to convince you very early on, but then he goes on, and on, and on and on and on, shooting down every possible objection and listing twenty-five bits of evidence for almost every sentence. By the time you get a third of the way through you will know more about the slightly-interestingly-shaped beaks of different species of finch than you ever thought possible.

This makes it sound like a bad book, but in fact it was a necessary book – if you want to convince people of a revolutionary idea, you have to overwhelm them with evidence, and Darwin spent literally decades of his life collating the evidence to prove his point.

But the most important thing he did (along with Alfred Russell Wallace, who came up with the idea independently when Darwin had nearly finished writing his book) was to come up with the idea of natural selection.

Like most great revolutionary new ideas, this was made up of a couple of old ideas that no-one else had ever thought of putting together before (this is not sarcasm – that is how most geniuses work). Darwin took Lamarckian evolution and added to it the idea, originally developed by Thomas Malthus, of competition for scarce resources. What he came up with was brilliant in its simplicity.

To take the example of the giraffe, used above when talking about Lamarck, imagine you have a load of horselike animals living in an environment where there’s not much grass, but there are plenty of bushes and trees. The horselike animals breed rapidly while living off the bushes, and when they breed some are naturally born with longer necks than others – not through any deliberate stretching, but just through normal variation in the same way some people are born with lighter or darker hair. And just like the colour of hair, their children will tend to inherit the slightly longer necks.

So eventually, so many horselike creatures are born that they eat all the bushes, and they start starving. However, the ones with the slightly longer necks can reach the lower leaves on the trees, and eat them and survive and breed. Eventually you have a population of longer-necked horselike creatures. They have then eaten so many of the lower leaves that only those who can reach the higher leaves will survive. Repeat this over many generations, and you have a giraffe.

And this simple process can explain, to the best of our current knowledge, all the near-infinite variety of lifeforms in the world, from the AIDS virus to the peacock to the plum tree to the mountain gorilla. All you need, to get to all that, is some stuff that breeds and eats, and not quite enough stuff for it to eat. Then wait a few hundred million years, and voila! You get a species of ape that seems destined to destroy it all…

That is what Darwin explained, and that is why Darwin is one of the handful of most important people who ever lived.

This entry was posted in books, science and tagged , , , , . Bookmark the permalink.

One Response to Hat And Beard 1 – Chuck D

  1. Ranald says:

    “the molecular basis of modern genetics was mostly worked out by Rosalind Franklin based on earlier work by Linus Pauling (then Crick & Watson put the finishing touches on Franklin’s work and took the credit for themselves).”

    I assume you’re just trying to be provocative here, but that’s nonsense. Crick & Watson pilfered some of Franklin’s experimental work without much in the way of credit, but the theoretical advances were theirs.

Comments are closed.