Evolution Of 'Irreducible Complexity' Explained
Using new techniques for resurrecting ancient genes, scientists have for the first time reconstructed the Darwinian evolution of an apparently "irreducibly complex" molecular system.
The research was led by Joe Thornton, assistant professor of biology at the University of Oregon's Center for Ecology and Evolutionary Biology, and will be published in the April 7 issue of SCIENCE.
How natural selection can drive the evolution of complex molecular systems -- those in which the function of each part depends on its interactions with the other parts--has been an unsolved issue in evolutionary biology. Advocates of Intelligent Design argue that such systems are "irreducibly complex" and thus incompatible with gradual evolution by natural selection.
"Our work demonstrates a fundamental error in the current challenges to Darwinism," said Thornton. "New techniques allowed us to see how ancient genes and their functions evolved hundreds of millions of years ago. We found that complexity evolved piecemeal through a process of Molecular Exploitation -- old genes, constrained by selection for entirely different functions, have been recruited by evolution to participate in new interactions and new functions."