however, geneticists have surprised themselves by finding evidence of recent and rapid changes in human genomes in response to the pressures of civilization. For example, fair skin allows more absorption of the sun's ultraviolet rays necessary for the skin to make vitamin D. So when the northern Europeans, living in a climate with little sunshine, started to farm wheat, a food low in vitamin D, they evolved fair skin to compensate and get more of the vitamin. There's a fine article at Spiked by Tim Black exposing what Robert* Malthus actually said. Malthus was a reactionary nostalgic pessimist who was not just wrong about population growth outstripping food supply. He was also wrong in his cynicism about helping the poor lest they breed more. (*Everybody calls him Thomas these days, whereas his contemporaries all called him Robert, which was his second name. Calling him Thomas is like calling the first director of the FBI John Hoover.) Mylecture on scientific heresyto the RSA this week has been reprinted onbishop-hill.netandwattsupwiththat.com, where it has generated much discussion. Thanks to Andrew Montford and Antony Watts for their interest. This Halloween, the United Nations declared over the summer, a baby will be born somewhere on Earth who will tip the world's population over seven billion for the first time. Truly do international bureaucrats have the power of prophecy! The precision is bunk, of course, or rather a public-relations gimmick. According to demographers, nobody knows the exact population of the world to within 100 million. (Incidentally,