Western man has stopped evolving: British geneticistOctober 7th, 2008 - 2:01 pm ICT by IANS
London, Oct 7 (IANS) Man in the developed world has stopped evolving, a British genetics expert has said, because they no longer have to struggle to survive and natural selection does not come into play any more.Going by his argument, any hopes of man evolving into something other than the current human state are left with the developing world, where tools of evolution are not thwarted in the absence of modern medi-care and higher standards of living.
Steve Jones, head of the department of genetics, evolution and environment at the University College London, says the forces driving evolution - such as natural selection and genetic mutation - no longer play an important role in our lives.
The people living one million years from now, should man survive, will resemble modern-day humans.
“We now know so much about the process of evolution that we can make some predictions about what might happen in future,” Jones said in a lecture here Monday.
Evolution is driven by natural selection and mutation. Genetic mutations create traits which, if helpful, give individuals a competitive edge over rivals.
Take natural selection. Before modernity, life was so tough that most children died before they reached adolescence. It was a race for survival and only the strongest made it, making out a case for natural selection. This means babies with genetic mutations that made them more resilient had better chances of survival as well as passing on their genes to their offspring.
Jones’ argument is that in a modern world of central heating and plenty of food, the same mutation is far less likely to give a child any advantage. A baby born today can expect to live a long and healthy life, which in turn works against the evolutionary tool of natural selection.
Referring to mutation, Jones expounds the view that it too is slowing down. It is because there are fewer older fathers in the West. Older men’s sperm deteriorates and contains more genetic mistakes which in turn can lead to mutations in their children.
Cell divisions in males increase with age. “Every time there is a cell division, there is a chance of a mistake, a mutation, an error,” he is quoted in The Times as saying.
A third factor - randomness - is also an important ingredient in evolution. Small populations that are isolated can change at random as genes are accidentally lost, he said. But as the world’s population becomes increasingly connected, the opportunity for random change is dwindling.
Jones said: “Worldwide, all populations are becoming connected and the opportunity for random change is dwindling. History is made in bed, but nowadays the beds are getting closer together. We are mixing into a global mass, and the future is brown.”
What he means is inbreeding is becoming less common as the globe becomes smaller.
Referring to Britain, Jones said: “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.”
Jones is not the only scientist to believe mankind will struggle to evolve from its present state. In his book “Future Evolution”, Peter Ward, a paleontologist at the University of Washington, claims that only by interbreeding and allowing bioengineering can a new species emerge.
But Chris Stringer, research leader in human origins at the Natural History Museum, London, said the idea that evolutionary pressures were no longer taking their toll on humanity was true of only Western civilization, according to Scotsman newspaper.
Another genetics expert, John Wilkins of the University of Melbourne, has already dismissed him.
Wilkins wrote on his personal blog: “Evolution has not stopped, nor even, I warrant, slowed appreciably. Sure, large populations tend to evolve less quickly than smaller ones for good stochastic reasons, but populations are partitioned.
“It may be in England that one’s partner has ancestry from a long way away, but there have been mass migrations in the human past before, in Africa when the cultural technique of animal herding spread southwards 2,000 years ago, and before that in the period from around 3000-1500 BCE from central Asia to Europe and back. Genes do not stay in one place for very long in evolutionary terms. Jones is mistaking small temporary effects for evolutionarily significant ones.”