Oh my God – it’s turning into a series.

In the last few years I’ve become increasingly interested in the relationship between evolution and neuroscience. As you’d imagine, there are as many theories about it as there are undiscovered skulls still out there. But here’s a precis of something I read in a scientific publication four years ago. (I’d give you the link to it, but my world wasn’t electronically archived in 2006.)

The author’s basic hypothesis – based on a close study of pre-history climate change, human skeletons and petrified stomach contents – was that man came down from the trees (because arid African conditions killed many trees) and then walked on two rather than four limbs (in order to see over the tall savannah).

This wasn’t original as a thought, but what the writer added was that Man needed more oxygen supply to the brain in order to outlast four-legged predators. That is, your sabre-tooth tiger could accelerate and take down Homo Erectus with relative ease. But Homo sapiens of the oxygenated bonce could keep going for longer – and very soon your big cat would get what people used to call ‘bonk’ (acute energy deprivation resulting in near collapse) before the word took on an entirely different athletic meaning. Thus, Homo sapiens survived more often, and Homo erectus died out.

Most oxygen in the body outside of the lungs is carried in the blood. To get more oxygen to the cranial consciousness centre meant more veins. And the only way to get more veins beneath the head’s sub-arachnoid zone was…more brain.

In short, the anthropologist’s conclusion was that the very high intelligence of Man is a by-product of evolution, not the point of it. I Googled this theory again recently, and the impression I get is that among your cutting-edge students of human development, it is the New Black.

The hypothesis intrigues me, for two reasons. First, it shows that our chances of getting any brighter as an evolving species are extremely slim. As a geneticist I met two Christmases ago explained to me in a dull moment between charades, none of the bodily relationships (in an engineering, gravitationally cantilevered sort of sense) would work if we evolved into beings either twice our current size – or grew the sort of enormous heads all movie aliens seem to enjoy. “We’d have to mate with a smaller species”, he asserted with an odd smile.

Second – and for me this is a lulu – the extrapolation proposes that evolution, to use the technical term, fucked up. It created a Mensa-level hooligan….and the rest is history. As in, a history during which Homo sapiens has used intellect to more dysfunctionally violent effect than any other earthly species of which we’re aware.

The comment thread on this one may well stretch to Mars and back, but actually I wouldn’t mind that. All I would say to get the thing going is this: if you believe in a Deity who is all-powerful, all knowing and altogether dead brilliant, the article I came across blows a bigger hole in that idea than Guy Gibson did in the Moehne Dam.

And even if, like me, you’re atheistically spiritual, it is also an own-goal in that it supports the chaos theory of which I am not at all fond.

Discuss.