The language of genes has become common parlance. We know they make your eyes blue, your hair curly or your nose straight. The media tells us that our genes control the risk of cancer, heart disease, alcoholism or Alzheimer’s. The cost of DNA sequencing has plummeted from billions of pounds to a few hundred, and gene-based advances in medicine hold huge promise. So we’ve all heard of genes, but how do they actually work? Arney is an award-winning science writer and broadcaster who specialises in genetics and biomedical science. 

PS The story goes that an old sea captain once gave Ernest Hemingway a six-toed cat whose distinctive descendants still roam the writer’s Florida estate…