Depressing though it may sound to those who identify more with the first rat's style of living, this biological process makes perfect evolutionary sense.

ECONOMIST: Obesity

Dr Carles Vila, from the Conservation and Evolutionary Genetics Group at the Donana Biological Station in Seville, Spain, said the debate was wide open.

BBC: Dog evolved 'on the waste dump'

Our form of conscious intelligence emerged from our evolutionary heritage, which in turn was shaped by our biological environment.

FORBES: What's the Likelihood of the Singularity? Part Two: Uploading the Brain

Maybe religion has no biological basis, but religiosity surely does and it must have been to our evolutionary advantage.

ECONOMIST: De facto Afghanistan