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Politics : The Environmentalist Thread -- Ignore unavailable to you. Want to Upgrade?

To: neolib who wrote (15671)	8/10/2007 8:38:25 PM
From: longnshort	Respond to of 36917

North America. 12,000 years ago, North America had an amazing Megafauna including condors with a sixteen-foot wingspan, ground sloths as big as hippos, three kinds of elephants, three kinds of cheetah and five other kinds of big cat, several kinds of pronghorn antelopes, long-legged, antelope-like pigs, an assortment of camel, llama, deer, horse, and bison species, giant wolves, giant bears and giant armadillos.? North America has been called a "super-Serengeti" with more big animal species than you would find in Africa. But 11,000 years ago, nearly all of these big animals - 70 species or 95% of the megafauna - disappeared completely. This is exactly the time when humans (Paleo-Indians) colonized North America, and their arrival and skill as hunters at that time is documented by the appearance of artifacts. The disappearing mammals in North America included all of the following: Mammoths Mastodons Horses Tapirs Camels Four-horned antelopes Ground sloths Peccaries Giant beaver Dire wolves Giant jaguar Saber-tooth cat *Some of these fossils are directly associated with human artifacts in archaeological sites. The carnivores on the list were probably not hunted directly, but were dependent on the large herbivores for food, so soon followed them to extinction. In some cases accurate dating methods have shown that certain species became extinct at exactly the times that humans arrived. Giant ground sloths and mountain goats in the Grand Canyon both went extinct 11,100 years ago, which is the time that the human hunters arrived (within the accuracy of dating methods, which is +200 years). There is also direct evidence for killing by humans. The human archeological sites from 11,000 years ago have stone projectile points, which were presumably used in hunting the large mammals. One mammoth skeleton has eight stone spear points among its ribs. Some of the large mammals were trapped in pits, and some were cornered using fire. La Brea tar pits and the Page Museum is an excellent place to see the fossils and reconstructions from this period. Mammoth Trumpet (a newsletter about the first Americans). Detailed study of late Pleistocene extinctions in North America (Martin, 1986) suggests that they happened over just a few hundred years. This explains why there is so little archaeological evidence for hunting of mammoths in the New World. The total number of mammoths from archeological sites in North America is 38; in Asia, where mammoths were hunted for many thousands of years, there are many more mammoth remains -e.g. remains of 1000 mammoths at just one site in Czechoslovakia and of 100,000 horses at another site. Paul Martin has suggested that the human population quickly expanded south from the Bering land bridge, and exterminated the big game as they went ("Blitzkrieg" model). Martin, P. S.1986. Refuting late Pleistocene extinction models. In Elliot, D.K. (ed) Dynamic extinction. Wiley and Sons, NY. 1073-130. Other authors have disputed the idea that human hunting finished off the Pleistocene megafauna of North America. For example, Donald Grayson, an archaeologist at the University of Washington, suggests that climate shifts and associated vegetation changes could have been responsible. Grayson disputes two aspects of the overkill hypothesis: 1. Out of the 35 genera that became extinct around this time, only 15 have been shown to have survived beyond 12,000 years ago. So 20 genera may have disappeared before human arrival. 2. There is good evidence for mammoth kills by the Clovis people, but no evidence that they hunted any other large mammals (he does not mention the evidence that they hunted two kinds of buffalo). Paul Martin responds that the Pleistocene megafauna had survived several climatic changes during the previous million years, some more severe than the one that occurred at the end of the Pleistocene. Yet these changes did not cause multiple extinctions. South America was also colonized by humans about eleven thousand years ago, and since that time it has lost 80% of its genera of large mammals, including ground sloths, horses, and mastodons.

To: neolib who wrote (15671)	8/10/2007 9:02:41 PM
From: one_less	Read Replies (1) \| Respond to of 36917

"There is plenty of evidence that much more modern large cultures collapsed from time to time, but we don't always know why." I'm not sure how that is responsive to my question about dominance. We don't always know the details or specifics but in general we know the kinds of things that cause collapses. In the case of culture it is always systemic corruption of one sort or other. Civilizations can be destroyed by cataclysmic natural events, disease, starvation, plague etc or by being conquered but never from the dominance of other creatures as far as I know. "100K primitive people don't dominate much of anything." You can speculate about some imaginary group if you want but I doubt you can find me even a small handful of actual people who've established themselves and who have not dominated over other creatures. Failing cultures and civilizations seems like a separate topic to me.