We know that evolution can be rapid, when dangers confront a species. The NY Times has an article which discusses the 50 year change in an endangered fish in the Hudson river from PCB contamination. A block of six bases was deleted from one gene to accomplish the feat. The mechanism for the gene change is not known.- James Shapiro is coming out with his book on his approach to evolution. Don't expect Darwin!!-http://www.amazon.com/Evolution-View-Century-James-Shapiro/dp/0132780933/ref=sr_1_1?ie=UTF8&s=books&qid=1308156663&sr=1-1