As the 20th-century novelist Joseph Conrad famously wrote, "It's only those who do nothing that make no mistakes, I suppose," and Nature is very busy, so she makes lots of them. But as a genius, she can use them to advantage. Take for example whole genome duplication -- an error in DNA replication, or mating between different species, that doubles the number of chromosomes, leading to a duplication of the vast majority of genes. Such grand mistakes turn out to be among the major forces accelerating evolution.