One can think of many explanations for why Neanderthals disappeared. Chris Stringer's ("A squalid habitat on the path to extinction", THES, March 26) is very peculiar.
The Gibraltar cave he is excavating has fossil evidence that Neanderthals crapped on the hearths, thus polluting their habitat. I can think of numerous examples of people using faeces as fuel in environments where wood is rare.
The possibility that Neanderthals came up with the idea of using their crap to get warm and to cook would suggest to me that they had identified an ingenious way to adapt to a harsh environment.
Daniela Burroni. Bradford University