Arrival of the Fittest: Solving Evolution’s Greatest Puzzle

Wagner, a professor at the Institute of Evolutionary Biology and Environmental Studies at the University of Zurich addresses the intriguing and long-standing question of how such a wide diversity of life arose. He doesn’t dispute the importance of natural selection, but argues that natural selection can only operate on the variability that exists; something more must permit nature to spread out in the manner it has. He concludes that mechanisms that lead to innovation are most important; innovations upon which natural selection can operate. Wagner discusses both the microbial and the multicellular world. In the former, horizontal gene transfer, the sharing of genetic material among individuals of many species, allows new genetic combinations to arise remarkably quickly. These are interesting results, presented clearly, but nothing new. His work becomes more remarkable when he discusses research, conducted largely in his laboratory, that demonstrates the number of ways there are to solve critical metabolic problems. One of his striking findings is that the mechanisms responsible for life are surprisingly robust: iterative mutations, far more often than anyone expected, can maintain and at times enhance an organism’s functionality. Wagner notes that “we can predict innovability even if we cannot predict individual innovations,” and his work further undercuts any arguments for intelligent design. (Oct.)