Cuckolded Fathers Are Actually Very Rare

TO GET someone else to do the hard work of bringing up your offspring for you is certainly one version of Darwinian success. Genetic analysis has shown it is indeed the case that many nests of many bird species harbour young not sired by the male who is helping to feed them. That led evolutionary biologists to predict something similar might be true for another couple-forming, home-building species, Homo sapiens. Rates of adultery in humans, though hard to pin down, and probably variable from on...