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Re: Erectus updated?Laurence A. Moore (larrymor@crl.com)4 Mar 1995 17:50:25 -0800
Tomas - Ran a quick search, and found these for you: "Based on a skull fragment [KNM-BC1] 2.4 million years old, scientists have pushed back the date of the emergence of man's ancestors by half a million years. // The fragment provided scientists with the first evidence that human ancestors in East Africa had made the crucial transition to the larger-brained genus Homo at a time coinciding with the earliest known examples of stone tools. // It also appeared to lend chronological support to a theory that the first species on the evolutionary path leading directly to modern humans appeared about 2.5 million years ago, in a period of dramatic climate change. // The discovery, reported in today's issue of the journal Nature, was made by scientists who took a new look at a three-inch skull fragment found near Lake Baringo in Kenya more than 25 years ago. /.../ The scientists concluded that the specimen is 'the earliest securely known fossil of our own genus found so far.' // As the path of human evolution is now delineated, the family that would lead to human beings diverged from the apes 5 million to 9 million years ago. // By 3.7 million years ago, these increasingly humanlike creatures walked on two legs, but still had small skulls and brains similar to those of modern chimpanzees. These creatures are the earliest known species in the genus Australopithecus. // The genus Homo diverged from Australopithecus from 2 million to 3 million years ago. The Australopithecine line became extinct about a million years ago. The earliest known Homo fossil, before the latest discovery, was 1.9 million years old. // The earliest recognized species in the genus, Homo habilis, meaning 'handy' man, emerged about 1.8 million years ago, judging from fossils found in Tanzania. Homo erectus, with an even larger brain, emerged 1.6 million years ago, and Homo sapiens, modern humans, evolved about 300,000 years ago." --- John Noble Wilford, New York Times, San Francisco Chronicle, 20 February 1992 "For more than 40 years, anthropologists have generally agreed that Homo erectus served as an evolutionary link between our earliest direct ancestor, Homo habilis, and modern Homo sapiens. This view holds that a hardy breed of H. erectus spread from Africa to Asia and Europe and lived from approximately 1.8 million to 400,000 years ago." --- Bruce Bower, Science News 141(25):408, 20 June 1992 "In spite of the contention, all parties can agree on one thing: The proto-human fossil record begins in Africa, with a species now called Homo erectus. After evolving in an African homeland, all concur, Homo erectus migrated to Europe and Asia about 1 million years ago. But after that, comes the Great Divide in paleoanthropology. // On one side of the divide is the Out of Africa group, counting among their number Christopher Stringer and Peter Andrews, both of the Natural History Museum, London, who think that only in Africa did the descendants of H. erectus give rise to modern humans. After evolving in Africa between 200,000 and 100,000 years ago, the out-of-Africa group says, modern humans spread throughout Europe, Asia and the rest of the Old World -- replacing other less advanced humans, such as Neanderthals. /.../ Regional continuity supporters argue that once Homo erectus spread throughout the Old World, its descendants continued to evolve in different regions, but interbred sufficiently to give rise to 'only one kind of modern human,' according to Washington University geneticist Alan Templeton. The main fossil evidence, offered up by the University of Michigan's Milford Wolpoff, is a series of crania of ancient H. erectus specimens from various world regions that show similarities to modern human skulls from the same regions." --- Ann Gibbons, "Reading the Bones for Modern Human Origins", Science 257(5072):875, 14 August 1992 "Members of the human evolutionary family left Africa and reached eastern Asia 800,000 years earlier than previously thought, according to a report in the Feb. 25 Science. // The new estimate comes from a redating of three Homo erectus specimens from the Indonesian island of Java. Local collectors found a skullcap of a child at one site in 1936 and partial skulls of two individuals at another site in 1974. The first skull now dates to about 1.8 million years ago, the latter specimens to approximately 1.6 million years ago." --- Bruce Bower, Science News 145(10):150, 5 March 1994 Hope those are helpful. - Larry
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