The second chart in my explanation of human evolution shows that monkeys produce much more DHEA than chimpanzees, with humans producing just a little less than chimps. As the brain increases in size, measurable levels of DHEA decline. This also follows the size of the denditions. Lots of DHEA means large teeth. My point in all of this, if you are still with me, is that a large brain means small teeth.
Bones are sensitive to testosterone.
Increased testosterone means stronger bones. Black women produce more testosterone than white women, and black women have fewer problems with osteoporosis than white women. Also, men have fewer problems with osteoporosis than women. Now, as humans evolved to produce increased testosterone, our bones and muscles became stronger and bigger. It is part of my theory that the increased testosterone triggered changes in the body before the brain increased.