8.10.2008, 11:20
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#21 |
| | Citim: Evolution is slowing down, says genetics expert
Human evolution is grinding to a halt, according to a leading genetics expert.
The message from Professor Steve Jones is that this is as good as it gets.
Mr Jones, from the Department of Genetics, Evolution and Environment at University College London, believes the mechanisms of evolution are winding down in the human race.
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At least in the developed world, humans are now as close to utopia as they are ever likely to be, he argues.
Speaking at a UCL Lunch Hour Lecture in London, Mr Jones said there were three components to evolution - natural selection, mutation and random change.
He said: "In ancient times half our children would have died by the age of 20. Now, in the Western world, 98% of them are surviving to the age of 21.
"Our life expectancy is now so good that eliminating all accidents and infectious diseases would only raise it by a further two years. Natural selection no longer has death as a handy tool."
Mutation rate was also slowing down, he said. While chemicals and radioactive pollution could cause genetic changes, one of the most important mutation triggers was advanced age in men.
"Perhaps surprisingly, the age of reproduction has gone down - the mean age of male reproduction means that most conceive no children after the age of 35," said Mr Jones. "Fewer older fathers means that, if anything, mutation is going down."
Random alterations to the human genetic blueprint were also less likely in a world that had become an ethnic melting pot, according to Mr Jones.
He said: "Humans are 10,000 times more common than we should be, according to the rules of the animal kingdom, and we have agri- culture to thank for that. Without farming, the world population would probably have reached half a million by now - about the size of the population of Glasgow.
"Small populations which are isolated can change - evolve - at random as genes are accidentally lost. Worldwide, all populations are becoming connected and the opportunity for random change is dwindling.
"Almost everywhere, inbreeding is becoming less common. In Britain, one marriage in 50 or so is between members of a different ethnic group, and the country is one of the most sexually open in the world. We are mixing into a global mass, and the future is brown."
He added: "So, if you are worried about what utopia is going to be like, don't; at least in the developed world, and at least for the time being, you are living in it now."
http://www.theherald.co.uk/news/othe...ics_expert.php | |
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