Post by Watchman on Jun 17, 2006 10:49:33 GMT -5
James Randerson / London Guardian | June 15 2006
The creation of a new species, something that scientific orthodoxy says should take thousands of years of genetic isolation has been achieved in the lab in just three months.
Scientists think they have recreated the process that produced a stunning South American butterfly called Heliconius heurippa virtually overnight. And they suggest that similar rapid species creation could help to explain puzzling groups of closely related species such as Darwin's finches and cichlid fish. The finding is yet another challenge to the charge from creationists that evolutionary biologists are unable to explain large scale evolutionary shifts that result in new species.
Biological dogma is that speciation, the process by which a new species forms, happens when two populations of the same species become separated for millennia by a new mountain range or a change in a river's course, for example. In their separate environments, the two diverge genetically and cannot mate when reunite. "The orthodoxy up to now is that it mostly has a destructive role," said George Turner, a professor of evolutionary biology at the University of Hull, "That's how species sometimes come to an end when they collapse into each other and all their unique adaptations are all mashed up together."
But Chris Jiggins at the University of Edinburgh and his colleagues were able to recreate butterflies with the same characteristics as H. heurippa after just three generations of breeding in the lab between two related parent species - H. melpomene and H. cydno.
"It was quite surprising how easy it was," said Dr Jiggins. "That really implies that the process of speciation could also have happened naturally very quickly." He said the process may explain the remarkable diversity among Heliconius butterflies. The research is reported in the journal Nature.