No one could accuse Diana Kennedy of cowardice. The 92-year-old Englishwoman lives in an adobe house in Michoacán, three hours west of Mexico City, where she writes about Mexican food culture. She has seen off extortion attempts by the local police. She isn’t bothered by nearby drug traffickers. She travels through the provinces of Mexico in an old jeep, in which she also sleeps. She takes a spade with her so she can dig the wheels out of the mud when necessary. ‘I never travel in straight lines,’ she says.

Neanderthals again, and why they died out. Of course, perhaps they didn't die out, and just mingled themselves into non-existence with us. I suspect we find that idea a bit distasteful, like discovering that we have the servants in our genes. Much better that they died of lacking something we most value that we had more and better of. The latest theory is that their eyes were too big. They've measured the orbits in the skulls and yes, they are larger than Homo sapiens skulls. So they saw better in the dark, but more of their brains were devoted to interpreting the messages from their great big eyes. Eyes bigger than their cerebral cortex. But Homo sapiens with their smaller, less efficient eyes, had room in their brain pan to develop their cerebral cortexes and use them for social networking and therefore learning and making the great cultural leap forward. Oh dear, yes, 'social networking' is the phrase they use. In my anthropological day, it was just called 'socialising'. But our clever brains are too smart to settle for mere socialising when they can come up with social networking. Evolution. There you have it in a nutshell, or a network.

Most African herbalists cause no more damage than dispensers of alternative medicines on our high streets. Every now and then, however, a sinister practitioner will advise a very special client that while roots and animal parts are useful, the most potent medicines are made from human blood, liver, spleen and heart. Yes, it is dreadful, he whispers, but there are unscrupulous people about, and I have heard that your rival is in the market for the stuff. What choice do you have? When one big man is persuaded, his peers are immediately alerted. In consequence medicine murders tend to crop up in clusters, the clients typically rich and powerful men. The anti-human sacrifice and trafficking unit of the Uganda police recorded 26 cases in 2008 and 28 in 2009, and a number of suspects were brought to trial. Enter Tim Whewell of the BBC’s Crossing Continents programme.