"Fatherhood" is rarer in nature than I realised

From an AEON essay, by an anthropologist who got into studying fatherhood:

In the first instance, as someone who began her graduate career as a primatologist, I knew that fathers who stick around, rather than hot-footing it as soon as copulation is complete, are vanishingly rare in the primate world, limited to a few South American monkey species and completely absent from the apes, with the exception of ourselves. Indeed, we are among the only 5 per cent of mammals who have investing fathers. I knew that, given the parsimonious nature of evolution, human fatherhood – with its complex anatomical, neural, physiological and behavioural changes – would not have emerged unless the investment that fathers make in their children is vital for the survival of our species.

The whole essay is interesting.  Go read.