Long ago, the Naked Mole Rats of the South African desert unlocked the potential of their species for reciprocal altruism: loving your neighbour as yourself. With unusually high levels of oxytocin, the hormone that forms bonds between mothers and babies and between people in love, they act in the best interests of the tribe. They live underground and are the only mammal not to be able to control their own temperature, which is always at the ambient temperature. If they lived in this country, they would not survive unless someone knitted them woolly jumpers, or they lived in a cosy lab somewhere.
It may be a co-incidence, but as well as living in a co-operative, self-sacrificial way, the mole rats have the longest life span of any rodent of equivalent size anywhere in the world. They also appear to be able to fend off cancer.