Unnatural Selection The wings of cliff swallows in Nebraska are getting shorter. On the Galapagos Islands, two species of finches are developing back into one. Increasing numbers of peregrine falcons are living in urban areas – and have adapted their behaviour. All of these changes have altered the course of evolution – in some surprising and unexpected ways. The process known as natural selection has now taken on another, quite different dimension: ‘Unnatural Selection’.
