Food Standards Agency report reveals 70% of supermarket chicken contaminated. Chicken: It's the nation's favourite meat. But today, a report released by the Food Standards Agency has revealed that around three quarters of that chicken is infected by campylobacter - a family of bacteria, 12 species of which are known to cause food poisoning. The estimated cost to the UK economy is £900 million per year. All supermarkets are implicated and all supply chains too. It doesn't cause outbreaks and thorough cooking kills all the bugs. Professor Hugh Pennington tells Dr Adam Rutherford why campylobacter is such a tough bug to crack. Can machines think? Neuroscientist, chess master and world-champion gamer, Demis Hassabis is this week's winner of the Royal Society's Mullard Award. In 2011, he founded an AI company, Deep Mind which was acquired by Google earlier this year for £400million.He tells Adam why he believes one of the best tests for artificial intelligence is an ability to learn how to play computer games. Why scientists study sex Sex between humans has long been something of a taboo for scientists. But the Institute of Sexology is tackling it head-on. It's a new exhibition at London's Wellcome Collection, a frank exploration of sex and the scientists who've studied it for the past century or so. Tracey Logan went to preview the display, and asked: Why do scientists study sex? Australopithecus discovery 40 years on 23rd November 2014 was a significant 40th birthday. Or, to be a bit more precise, it was a 3 million, 200 thousand and 40th birthday. On that day in 1974, Donald Johanson and his team in Ethiopia discovered the fossilised remains of AL 288-1, who became universally known as Lucy. Don talks to Adam Rutherford about the young woman who changed his life. Producer: Anna Buckley & Fiona Roberts Assistant Producer: Jen Whyntie.