Cro-magnon people, the ones we are most like, appear in the fossil record only 30,000-50,000 years ago. Neanderthals go back much further, more than 250,000 years. Yet they had fire, made tools, buried their dead with possessions (so apparantly had a concept of an afterlife), and had, on average, slightly larger brains than do modern humans, as well as much more robust skeletal structure. They overlapped in time, that is, both species existed simultaneously for some thousands of years, but eventually Cro-Magnon people replaced Neanderthals everywhere. It is not certain whether Neanderthals were killed by the newer Cro-Magnons, or they just died out. One idea was that Cro-Magnons, and therefore ourselves, represent an immature Neanderthal, that is, one which had not yet passed puberty. Skeletal studies have shown that young Neandertals, including infants, children, and young adolescents, did not yet have the brow ridges, and protruding jaw and general skull shape we associate with Neanderthal. So perhaps something changed genetically which allowed Neanderthals to mature sexually without adopting the full skeletal development which we associate with the classic Neanderthal. This would explain why some features associated with Neaderthals sometimes appear in "modern" humans as rare traits. I have personally seen people with the steeply sloping forehead and brow ridges, although they appeared "normal" in every other respect. Before Neanderthals, there were earlier hominids which appear less and less like us, and having more in common with apes the further back in time one goes. There has been a number of good novels written based on new knowledge of early humans, "Clan of the Cave Bear", by Jean Auel, "The Animal Wife" and "Reindeer Moon" (forgot the author), and "Dawn Land" by Joseph Bruchac.
