8 - The Emergence and Spread of Homo sapiens

Summary

There is little, if anything, in the hominin fossil record that can be said to closely anticipate the very derived anatomy of our species Homo sapiens. Compared to other members of the genus Homo, modern humans are exceptionally slenderly built, with narrow hips and barrel-shaped rib cages that taper both at the top and the bottom. Our skulls are high, short, and rounded (Figure 8.1); and instead of projecting, our very small faces are retracted beneath the front of our braincases. Our brow ridges vary from modestly protrusive to barely detectable, but they are invariably bipartite, with central and lateral surfaces separated by an oblique furrow. We are also alone among the hominins in having a true chin at the front of the lower jaw. This takes the form of an inverted “T,” with a vertical ridge in the midline of the jaw atop a horizontal bar running between a pronounced tubercle on each side.