Book excerpt: 'A gripping and sobering reminder of how much we are all governed by our genetic inheritance. So much for free will.' The Mail on Sunday Stress, obesity, poor mental health, drug addiction, bowel diseases, violence and fake news; a stark checklist of modern world problems and every one of them is an echo of our evolutionary past. In Unfit for Purpose, biologist and broadcaster Adam Hart explores the mismatch between our fundamental biology and the modern world we have created. In each chapter Adam reveals the many ways in which biological adaptations that evolved to help us survive and thrive now work against us. For example, in the modern world stress is a killer but how did 'fight or flight' instincts turn from life-savers to life-takers? Obesity is a disease now but is it also just a side-effect of our evolutionary past? Whether it's the derailing of microbes in our gut, the rise of gluten and lactose intolerance, problems of social media or drug addiction, we always seem to have one foot in the modern world and the other firmly in our evolutionary past. Adam explores science, archaeology, medicine, genetics, sociology and more, to show how, in a modern world of our own making, we find ourselves 'unfit for purpose'. But all is not lost! In unpicking the causes of our current woes, he unearths some secrets of evolutionarily informed treatments that will change the way we think about ourselves and our future.