Abstract
Richard Dawkins' defense of Darwinism, which he describes as a climb up the "backside of 'Mount Improbable'," is challenged by direct observations of the evolution of RNA viruses, whose mutation rates are a million times faster than that of other organisms. These studies suggest severe limitations to gradualism, or "descent with modification" that Dawkins insists is an essentially complete explanation of origins. Comparisons of the genomes and biochemical machinery of viruses, as well as those of simple single-celled organisms, suggest that numerous lateral transfers of genetic material, or other non-Darwinian "saltations," are needed for a naturalistic explanation of origins.