RE: Yukon fossils represent a pivotal moment in evolution
June 18, 2011 at 10:53 am
(This post was last modified: June 19, 2011 at 2:32 am by Anomalocaris.)
It doesn't actually matter whether HN and HE outside of africa were technically capable of producing fertile offsprings with HS, Min. it doesn't even matter if there were already bonafide HS in euroasia prior to when OOA placed the first departure of HSS from Africa. The OOA hypothesis hinges on whether the current HSS population in euroasia predominantly descended from an migration of Bonafide HS out of Africa. Genetic evidence says it was.
As to the innuit and Watusi, you know well that is an emotive but disingenuous comparison. 1st. OOA deals with origin of HSS outside of Africa. Without knowing the specific genetic makeup of Watusi, who presumably came from inside of Africa, you don't know how their ancestors fit within the narrative of the OOA. 2nd, even so, you know well that genetically, innuit and Watusi are very close, having shared one common maternal ancester within about 120,000 years. Take away those adaptive morphological changes which can be shown to have very recently been forced by their present environmental conditions, what remains is also morphologically similar, far more similar than between either group and HN or HE.
As to our possible relationship with HE, the question really is not whether that was so. Some way or another HS descended from HE. The question is, if it were so, did it happen again and again after HS had already arisen. Here the morphological evidence argues against it. The Inuit and the Watsui may differ greatly in skin color, height, certain fine facial features, but they there are no traits such that, if an offspring were to possees something like an average of the features of his parent, that would by itself severely imperil his survival. Not so between HE and HSS. HSS possess a child growth pattern that is unique amongst primates. Unlike all other primates, we are born with our central nervous system morphologically already close to full development. We are not just big brained, we are born big brained. To make this possible, the pelvic girdles of HS females are also unique. Modern woman are wide hipped in comparison to HE woman because the birth canal must accommodate the passage of a full sized brain. If a HE woman were to attempt to give birth to a infant with a mix of HS and HE growth characteristics, the birth would likely be exceedingly difficult, probably killing both the mother and infant in the process. If a HS woman were to give birth to the same, the birth itself might be successful, but it seems unlikely the offspring would develop normally with his age peers, would likely die an outcast.
As to the innuit and Watusi, you know well that is an emotive but disingenuous comparison. 1st. OOA deals with origin of HSS outside of Africa. Without knowing the specific genetic makeup of Watusi, who presumably came from inside of Africa, you don't know how their ancestors fit within the narrative of the OOA. 2nd, even so, you know well that genetically, innuit and Watusi are very close, having shared one common maternal ancester within about 120,000 years. Take away those adaptive morphological changes which can be shown to have very recently been forced by their present environmental conditions, what remains is also morphologically similar, far more similar than between either group and HN or HE.
As to our possible relationship with HE, the question really is not whether that was so. Some way or another HS descended from HE. The question is, if it were so, did it happen again and again after HS had already arisen. Here the morphological evidence argues against it. The Inuit and the Watsui may differ greatly in skin color, height, certain fine facial features, but they there are no traits such that, if an offspring were to possees something like an average of the features of his parent, that would by itself severely imperil his survival. Not so between HE and HSS. HSS possess a child growth pattern that is unique amongst primates. Unlike all other primates, we are born with our central nervous system morphologically already close to full development. We are not just big brained, we are born big brained. To make this possible, the pelvic girdles of HS females are also unique. Modern woman are wide hipped in comparison to HE woman because the birth canal must accommodate the passage of a full sized brain. If a HE woman were to attempt to give birth to a infant with a mix of HS and HE growth characteristics, the birth would likely be exceedingly difficult, probably killing both the mother and infant in the process. If a HS woman were to give birth to the same, the birth itself might be successful, but it seems unlikely the offspring would develop normally with his age peers, would likely die an outcast.
