Throughout the evolution of Earth's life, various species have come and gone. The Neanderthals in particular lived for around 326 000 years overall; they obeyed certain laws of ecology just like many other living creatures. Yet, just like numerous other living creatures, these laws ultimately led to their demise and subsequent extinction. Additionally, the arrival of our immediate forerunners, the first "true" humans, also played a large part in their extermination because they learned how to work around these laws.
""When we try to pick out anything by itself, we find it hitched to everything else in the universe." -- John Muir." In other words, "everything is connected to everything else" (Chapter 3 - Commoner's Laws of Ecology). The Neanderthals were much better adapted to living in Ice Age Europe and the Middle East when compared to our ancestors who have evolved in ever-tropical Africa:
"Their bodies were rugged. (...) In contrast with the lean, equatorial body of African Homo erectus almost 1.4 million years earlier, the Neanderthal body was heavy and broad (...) Their overall body proportions and relative lengths of arm and leg bones were indicative of populations with a long history in cold climates." (Potts, 1997: 218)
However, when our predecessors appeared on the scene, these greatly adapted Neanderthals began to disappear. Why? It is due to that fact that "everything is always changing" (Chapter 3 - Commoner's Laws of Ecology). The Neanderthals became too specialized, too rigidly dependant to their habitat - various montane valleys and hills of Europe and the Middle East. In contrast, our ancestors always had evolved towards greater versatility. In particular, the Neanderthals' fossil sites were found in caves, whether in Europe, or Central Asia, or the Middle East, suggesting that they had a certain tendency to become dependant on them (Stringer and Andrews, 2005: 165). Though they were nomad people (i.e. better adapted to surviving outside in the Ice Age weather), they used the caves mostly for food storage and not for permanent habitation:
"(...) such occupation appear to have been rather short--weeks, perhaps, rather than months--and in many cave sites, especially, there is evidence that carnivores moved in during the times when no hominid occupants were in residence." (Tattersall & Schwartz, 2000: 209)
Moreover, our human ancestors also started to use the caves as residences, but their approach was different from the Neanderthals. Our ancestors, less adapted and specialized to the life in the open during an Ice Age winter, tended to make the caves their permanent residents instead, cutting the Neanderthals off from this resource. (McKie, 2000: 200-2)
With their habitat gone, taken over by our forerunners, the Neanderthals died out. Meanwhile, our forerunners had something else that the physically superior Neanderthals lacked. They had superior culture, for "(...) about 40 000 years ago, a cultural explosion swept through Homo sapiens", enabling them to create new, more complex tools, first works of arts and houses (McKie, 2000: 193-4) than ever before; something that the Neanderthals failed to achieve or develop. Their own - quite practical and intelligent - brains were not up to the task of matching the imaginative brains of our forerunners. Their generalization, as being more adaptable, in combination with the change in the ecosystem created by their arrival in Europe and Near East triumphed over Neanderthals' specialization. Consequently, our mentally superior forerunners defeated the physically superior Neanderthals. The last hurdle for the Homo sapiens specie was gone. Now, they, with their imaginative and problem-solving brain, were going to take over the Earth.
Bibliography
McKie, Robert
2000 DAWN OF MAN. The story of human evolution. London: BBC Worldwide Ltd.
Potts, Rick
1997 Humanity's Descent. New York: The Hearst Corporation.
Stringer, Chris, and Peter Andrews
2005 The Complete World of Human Evolution. London: Thames & Hudson Ltd.
Tattersall, Ian, and Jeffrey Schwartz
2000 Extinct humans. New York: Westview Press.
University of Maine Cooperative Extension
03/20/07 Chapter 3 - Commoner's Laws of Ecology. Electronic document, http://www.umaine.edu/umext/earthconnections/earth/chapter3.htm, accessed September 12, 2007