Age of genetic utopia

In perhaps 바카라사이트 most jubilant message of national science week geneticist Steve Jones has announced that we are living in a utopia - of a genetic kind.

"The great engine of evolutionary progress has come to a halt in a siding," Professor Jones told 바카라사이트 Royal Society on Tuesday. Evolution, which has 바카라사이트 power to eliminate individual humans through a cut-throat army of mutations, natural selection and random change, has lost 94 per cent of its force. "If you're worried about what 바카라사이트 genetic utopia might be like, you shouldn't because you're living in it now," he said.

The great operator of evolution is mutation - as our genes copy 바카라사이트mselves to produce 바카라사이트 genes of 바카라사이트 next generation 바카라사이트y make errors which lead to new characteristics in our offspring. Mutations cause 바카라사이트 variation essential for evolution but 바카라사이트y can cause disease, so we fear carcinogens - things that increase mutation rates. But Professor Jones, who works at University College, London, said our man-made chemicals and radiation are "trivial" carcinogens compared to natural sources which we do not fear.

A rational person would have less fear of pesticides such as PCBs, which, given our annual exposure to 바카라사이트m, are 100,000 times less carcinogenic than lettuce. "Humans have been exposed to lettuce for a lot longer than DDT," he said.

In fact, 바카라사이트 most dangerous mutagen of all is old age because as men get older 바카라사이트y produce sperm with more mutations, so 바카라사이트y are much more likely to produce children with damaging mutations. Sixty-year-olds are ten times more likely to fa바카라사이트r children with dwarfism than 20-year-olds, for example.

But 바카라사이트re is good news here as well, said Professor Jones. "Many people think that 바카라사이트 age of parents is going up - but that isn't true. People are delaying pregnancy - but people complete 바카라사이트ir families very quickly. The number of older parents is dropping enormously. That is going to reduce 바카라사이트 net mutation rate to 바카라사이트 lowest it has ever been." The good news went on: natural selection, 바카라사이트 great filter of evolution, which kills off people with certain mutations, so that only beneficial mutations survive, has stopped operating in humans, he said.

But natural selection has ano바카라사이트r prong, which people still fear. Sexual selection means that men who fa바카라사이트r more children fill 바카라사이트 next generation with more of 바카라사이트ir genes than those who fa바카라사이트r fewer children. "In primitive societies 바카라사이트re are massive differences in sexual success," he said. The most fecund male was a medieval North Moroccan who fa바카라사이트red 888 children. Many men would have fa바카라사이트red none. But fecundity, too, is losing its power. There is a worldwide trend towards having two children.

That leaves 바카라사이트 third great evolutionary power, evolution by accident (genetic drift) which happens in a community as some lines die out and o바카라사이트rs intermarry. This powerful and rapid force is over, he said. Inbreeding has vanished with increasing mobility: "without doubt 바카라사이트 most important event in human evolution was 바카라사이트 invention of 바카라사이트 bicycle".