DA. I cannot actually remember attending a party where an australopithecus was present but I may have. I can't remember much of some parties.
It would actually be interesting to know how far back we would have to go before we reached an ancestor modern humans could not form fertile hybrids with. Although it's not totally a function of time, for most pairs of mammal species one million years is not sufficien. Beyond that infertility appears in the male offspring. By two or three million years both sexes are infertile. Beyond four million no offspring at all.
In spite of artists efforts we actually have no idea when the modern human hair pattern developed. Perhaps it had happened by Australopithecus times, especially in the tropical populations. There is a saying in NZ you don't look at the fireplace when you stoke the fire. Australopithecus females may have been quite cute. The males seem to have been big and fierce but many women today are attracted by that sort of thing.
