although I agree it does seem to have particular relevance to human, and some other ape behaviour because we are largely tribal animals.
Yeah, that was what I meant by referring to kin selection as a specifically human activity, but I realise I could have been more careful with my words, or at least provided a parenthetical explanation. The way I said it, ants are more human than we are. Sorry about that.
And no, I don't really think that there is anything about human nature that sets us apart
from nature, however, I do think that, unlike "cat" nature, human nature does have a few peculiarities which set it completely apart from other natures
(though not from Nature
.) Retractile claws are just a specialized form of regular claws, all mammals like milk (by definition!), and whiskers or some functionally equivalent structure (such as feelers) are present in a wide variety of animals. Language and morality aren't. Not saying they're better than whiskers or nightvision, just that they're entirely
different, because they have a sort of metaphysical
existence. A language or a moral concept is not a biological or physical reality, but a non-physical thing (a meme, if you will.) My point is that human nature can be defined by the existence of such metaphysical concepts.
Evidently, it is still impossible to draw a sharp boundary in time which would delimit "human" nature, as arcAngle pointed out. Australopithecines probably had a bit of what we call human nature, so do chimps. Anything in the genus Homo
probably had a lot of it. Some humans alive today probably have more of it than others. However, it still remains pretty clear as something we can define as "human" rather than "feline" or "chair" nature.