Hey LindaLou, I am not a scientist...don't really study this stuff in depth. My impression, though, as a lay person is just that there can be humans, even, with malformations here and there. There are different head shapes. For example - my head is wide in the back with a large circumference where you measure. My daughter's head is shaped the same and went off the charts when she was an infant so being a teaching hospital they wanted to run tests on her to make sure all was well. I got ticked after they tortured her trying to find a vein to use...it really wasn't necessary and I should've refused, but of course having that doubt thrown in there wanted to make sure she was fine. I have a big head. Not sure how to post pics on here but will try and show it somewhere if I can. My husband has a narrower head that taller. And I posted some time ago, we have a friend who is a genius, in fact, quite literally, who they use to call Commander Ledge b ecause of how his forehead came out and over his eye sockets. Yet he doesn't look like a neanderthal. (He is on the web, I'll see if I can find a pic that shows it). There are variations in shapes and sizes. I don't see where that is such a big subject for debate. Is there evidence to show that whole societies had those same type skulls? Even if that is the case, if they were related genetically, so what? I use to tell my sister she had a grape face.....I think my husband has what I call potatoe feet. I just don't see how so much about the creation can be construed from such things....

If I missed something let me know - I may've missed the point of your question altogether. I'll look at the mitochondrial Eve too. I'm sure you know more than I do as far as your question about the heads and what makes them human or not....but still - I just don't see where variations in old skulls prove anything. They could be ape variants (chimps or relatives)skulls, too. Not an expert....