Thinking outside the paleoanthropological box for a second.... I recently mentioned the great book The Eternal Frontier. It tells the tale of North America's natural history from ~ 60 million years ago to the present. As the author approaches 11,000 years BP-he has to address a conundrum. It goes like this. Before 11,000 years ago North America was filled with mega-fauna that roamed the wilderness without the fear of "man the hunter." Then the ancestors of modern Native Americans crossed Beringia and a "blitzkrieg" occurred. Over 300 years most of the mega-fauna became extinct [1]. Many of the large mammals that we associate with the American west, the grizzly, bison and wolves, almost certainly fill niches vacated by the extinct ungulates and their predators. In fact, they pushed south from Beringia in the wake of the Clovis people. This theory was the dominant paradigm for several decades, and its elegant simplicity is bewitching. The presence of pre-Clovis sites such as Monte Verde were long dismissed. No more. They can not be ignored, and have to be accounted for. The author of The Eternal Frontier acknowledges this. But he can't think of any way to square the circle-so he simply ignores the pre-Clovis sites and tells his tale as if the Clovis blitzkrieg still held (he admits this)! The author states quite sincerely that the mega-faunal extinction is simply too closely associated with the Clovis people to have any other explanation. He can not imagine why the pre-Clovis populations would not have caused the same extinctions, as the example of ancient Australia illustrates that even populations with primitive tool-kits can decimate the indigenous biota. One point to make is that new theories postulate that the large ungulates might have been killed by diseases that the Paleo-Indians brought with them. This might explain why the pre-Clovis people did not cause any extinctions: they came before the potent pathogens had evolved in Asia. But there is something else that we might consider: human biodiversity. Let me explain. The author of The Eternal Frontier can not imagine that pre-Clovis people were any different than the Paleo-Indians. Perhaps they looked a bit different, and had different technologies, but their needs and potentialities would be the same. Given the same context and stimuli, they should have had the same effect on the indigenous wildlife as the Paleo-Indians. But they obviously didn't. But what if one reason that the pre-Clovis people had a less deleterious effect on the American biota was that they themselves were different in some essential fashion? The individual than runs a website devoted to the Andaman Islanders has noted that an ancient pre-Clovis skull found in Brazil looks to him like a pygmy. If the pre-Clovis people were pygmies, to use one example, their nutritional needs would probably be lower, and so they would have been far less likely to over-exploit or even target the mega-fauna. In addition, the aforementioned website catalogs in detail the physiological peculiarities of the Andaman Islanders, so it would not be wholly implausible that they were not carrying the same suite of pathegons as the Paleo-Indians. In any case, this is just speculation. But the diversity of the pre-Columbian people is only beginning to be explored. Cut off from the homogenizing brutality of Eurasia, who knows what sort of wondrous micro-races might have developed before being swept away from the view of history by the Paleo-Indians? [1] Modern Native Americans south of the polar regions are divided into two groups, the Na-Dene, who represent the Indians of the Pacific Northwest and Alaska as well as a few splinter groups such as the Apache and Navajo, and the Amerinds, who are all other Native American groups. The Na-Dene are relative latecomers, while the Amerinds are probably the descendents of the Clovis people.