How the Genome Readies Itself for Evolution

Genetic change, and hence the evolution of new species, is commonly thought to result from small, random mutations in individual genes, but a growing wealth of data emphasizes that that perception is wrong. Indeed, the mutations leading to evolutionary change can involve the wholesale shuffling or duplication of the genetic material, changes that can affect the expression of genes or free up duplicated genes to evolve new functions. What9s more, these changes may not be totally random: Researchers have found, for example, that some parts of the genome are more likely to be duplicated or moved to another place than others, depending on the nature of their DNA sequences. They are also learning that the enzymes that copy and maintain the DNA introduce changes in some parts of the genome and not others, creating hotspots of mutation that increase the efficiency of evolution.