|The Early Days of a Better Nation|
Tuesday, March 03, 2009
'I'm a geneticist. My job is to make sex boring.' That, said Steve Jones, is how he introduces his lecture course to his students. 'They look a bit puzzled, but after 25 lectures, they get it.'
I doubt that Steve Jones could make anything boring. His lecture 'Lost Worlds and Worlds to Come' was an hour well spent. Here are some scrappy notes.
The Lost World is placed, like More's Utopia, in an isolated New World setting - cue a slide of the actual plateau, Mount Roraima, which had inspired Doyle. (That's typical of how Jones used slides throughout - each one was unexpected and made a point stick.) The utopian genre (Jones said) changed in the 1890s, with biological change replacing social change. Slide of 1950s paperback cover of The Time Machine. Next instance: Star Trek, which Jones said showed a society almost identical to ours in terms of social institutions, but with great variation in human bodily form. (I suppose the absence of money is less visible than the presence of pointy ears.) Even more oddly, this point was illustrated with a slide of one of the Ferengi, which Jones seemed to think was supposed to be a future variant of the human species. But (returning to the serious science) such changes to the human species, Jones argued, are not going to happen. Evolution is 'descent with modification', or in a more modern formulation, 'genetics plus time'. Its drivers are mutation and selection.
Mutation was illustrated by a picture of Boris Johnson, 'British mutant'. The London Mayor's shock of yellow hair is the result of a mutation which has had a selective advantage in Northwest Europe. Light skin colour maps almost exactly to areas where Vitamin D deficiency, due to lack of sunlight, is a problem. (Point-sticking slide: graph showing significant difference in Vitamin D levels in the blood of European-Americans and African-Americans.) Blue-eyed blondes are a further twist in this tale: Northwest Europe, because of the Gulf Stream, is the only region where grain crops can be grown that far north. Grain crops are not only lacking in Vitamin D - eating their food products actually removes Vitamin D from the blood. This confers an advantage on skin types even more light-sensitive and melanin-deficient than the European norm. Natural blondes, sadly enough, are just people who can live on oats in the rain.
Both mutation and selection have dropped radically in the advanced countries. The main mutagen is not radiation but men, specifically older fathers. In developed, and increasingly in developing, countries, few men have children after the age of about 40. Slide of graph showing ages of fatherhood in West Africa, Pakistan, and France: the differences were striking. At the same time, the proportion of babies surviving to adulthood has gone from about half to almost all in a few centuries. Even the disparities in reproductive success between classes has dropped. Hence Jones's surprising claim that human evolution is over, at least for now. Isolation is another factor of evolution that has been drastically reduced. An easy way to track genes is to track surnames: in less than a century the Joneses have spread from being 'behind the electrified fence of the Welsh border' to adjacent areas of England, and can now even be found in London. In Australia, Professor Jones saw a T-shirt slogan that amused him: 'Reunite Gondwanaland'. That, he said, is exactly what we're doing: in terms of gene flow within the human population, we're living on one gigantic supercontinent. 'If you're worrying about what the lost world of the future will actually be like, you shouldn't, because you're already in it.'
In the Q&A afterwards I tried to think of a polite way to set the distinguished geneticist straight about the all-important Ferengi question, and it's just as well that I couldn't. The Ferengi may seem ridiculous as future humans, but it's even more ridiculous that they are aliens.