HumansWhen does a bone become a fossil? As organic material in a bone gets replaced by minerals over time, it becomes a fossil. But that can happen at different rates even within the same individual 51¶¯Âþ
VideoSeventh Son author Sebastian Faulks: 'I'm 3.7 per cent Neanderthal' Our 51¶¯Âþ Book Club has been reading Sebastian Faulks's The Seventh Son, a futuristic sci-fi thriller  exploring ethics, genetics and what it is to be human. Video