Implications of the Sahelanthropus Tchadensis (Toumai) Discovery
Compared to the complete history of life on earth, human history is relatively brief. The earth is billions of years old and living organisms probably appeared some two to four billion years ago. Many different kinds of animals have been inhabiting the earth for hundreds of millions of years. Early hominids which are human like creatures are thought to have originated just 5 million years ago and modern humans around 100,000 years ago. There have been a recent discovery that is now challenging the appearance of the early hominids.
In the country of Chad which is located in central Africa scientists have recently made a discovery of a hominid skull. This skull was dated back to between 6 and 7 million years ago. The discovery was led by anthropologist Michel Brunet from the University of Poitiers in France. The find was named Sahelanthropus tchadensis and is nicknamed “Toumai” which means “hope of life” in an African language. The fossil find is an almost complete skull, some teeth, and a few fragments of the lower jaw. (Bower 2002)
This fossil find is completely surprising and amazing. The remains that were found represent the earliest known member in the line of human evolution. This find could be the beginning of many which could completely change our current ideas of human evolution. This pushes back the dates of human history by 2 million years. If Toumai is truly a common ancestor of humans and chimpanzees this makes the molecular clock theory wrong. The molecular clock dates the divergence of humans and chimpanzees somewhere around 5 million years ago while the Toumai discovery suggests that is was 6 to 7 million years ago. (Bower 2002)
Homini...
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...of the same kind. This is only one very small link in the massive chain of human origin. Scientists need to continue to search the globe and make more new discoveries to further challenge the norm and uncover the truth of our history.
Sources:
Bower, Bruce. Evolutions surprise: fossil find uproots our early ancestors. Science News 13 July 2002; vol. 162, No. 2, P. 19. 4 April 2004
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Brunet, Michel. A new hominid from the Upper Miocene of Chad, Central Africa. Nature 418, 145-151. 11 July 2002. 4 April 2002
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Paoli, Laurence. Toumai: Shaking our conceptions on the earliest steps of Hominid history. Science In Africa August 2002. 5 April 2004
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Whitfield, John. Oldest member of the human family found. Nature News Service/Macmillan Magazines 11 July 2002. 4 April 2004
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Humanity became fascinated with the idea of evolution with the work of Charles Darwin and the Scientific Revolution. People began hunting for fossils that would prove that man had an ape derived ancestry (Weiner, 1955). After various years of searching, a piece of physical evidence was found in England that was said to confirm the theory of evolution (Weiner, 1955).This confirmation came from Charles Dawson’s discoveries from 1908, that were announced publicly in 1912 (Thackeray, 2011). Dawson was believed to have found the fossil remains of the “missing link” between ape and human evolution, the reconstructed skull of Piltdown man (Augustine, 2006). The material was found in stratigraphical evidence and animal remains that were, at the time, adequate enough to confirm the antiquity of the remains (Weiner, 1955). In 1915, another specimen, Piltdown man II, was found further proving this theory (Augustine, 2006). However, this was merely a hoax proven by fluorine relative dating in 1953; the artifacts and bone fragments discovered turned out to be altered to fit the proposed scenario (Augustine, 2006). The skull found was actually composed of a human braincase that was younger than the complimentary orangutan lower jaw (Falk, 2011). Both sections of the skull had been stained to appear to be from the same person of the same age (Falk, 2011).The perpetrator of this act was never caught and there are many theories proposed for the motive of this hoax (Augustine, 2006). Many people have been taken into consideration for this crime, such as Chardin, Woodward, Hinton, and Dawson (Augustine, 2006). Nevertheless, the evidence that proves that Dawson is guilty of this crime against anthropology is quite substantial compared to the evidence...
Over the last few hundred years, more and more has been added to the world’s fossil collection, fossils from all over the world. New theories have been created and old theories have almost been proven about the evolution of man. For example, we have proof that different species of man existed with certain types of DNA sequences and instincts, some we may not have anymore, or some that other species did not have back then. Even though it is subjected to much debate, one of the most widely accepted theories however, is that Homo sapiens interbred with the slightly more primitive species of man, the Neanderthal.
A study performed by Martin Hausler and Peter Schmid of the University of Zurich, Switzerland, appeared in the October 1995 issue of Journal of Human Evolution, igniting controversy over the 1974 Australopithecus discoveries in Hadar, Ethiopia. The most famous of the Hadar specimens is the 3-million-year-old skeleton, “Lucy,” who was recovered by paleoanthropologist, Donald Johanson. In his article, Shreeve presents the methods and findings of Hausler and Schmid’s study as well as some counter arguments from other scientists in the field.
There was a chief new discovery of fossil bones and teeth belonging to the earliest human ancestors ever discovered. The fossil bones predate the oldest formerly discovered human ancestor by more than a million years. The discovery was of fossil remains of a hominid that lived in present day Ethiopia between 5.2 and 9.8 million years ago. (Hominids include all species following the split as of the chimpanzees on the “human” side of the evolutionary tree.)
These fossils are having a major impact on the scientific world’s view of human evolution and scientists may even have to rethink some present ideas about it. Because the skull of Toumai has characteristics that are very similar to those found in the Homo family, some scientists are beginning to question whether or not Australopithecus, an early member of the hominid family from about four to one million years ago and they are characterized by their fully upright posture and their small brain size, is even part of the evolution record of humans from apes. Bernard Wood, of George Washington University in Washington DC, argues that if Australopithecus has more ape-like features than the features found on an older
Trinkaus, E. (2007). European early modern humans and the fate of the Neandertals. Proceedings Of The National Academy Of Sciences Of The United States Of America, 104(18), 7367-7372. doi:10.1073/pnas.0702214104
Australopithecus afarensis who existed 3.5 million years ago and a 4.4 million year old skeleton of an Ardipithecus ramidus are the closest science has come to discovering the human lineage. Shattered Ancestry an article written by Katherine Harmon discusses the remains of two hominids found within Ethiopia. These skeletal remains have created a huge controversy within the topic of evolution questioning many assumptions that have been made referencing the human lineage. The skeleton of the Australopithecus afarensis was named Lucy and was discovered in 1974. The evidence of her walking upright on her two feet essentially guaranteed her a spot in the human lineage line. Lucy was a chimplike ape that was said to walk upright making scientists believe the human ancestry was simple. The complete skeleton found in Ethiopia of an Ardipithecus ramidus named Ardi completely changed all assumptions made from scientists about the complexity of the human lineage. These remains have encouraged researches that the human line is not the only lineage to have evolved but the chimpanzee line has undergone drastic changes as well. There are many traits that researchers have always directly linked to the human lineage however since these discoveries occurred researchers are reconsidering. The recent discoveries that have shattered what has always suggested what linked a species to the human lineage have changed the certainty of whether it is possible to confidently identify the human’s last common ancestor. Majority of scientist had forgotten that there would have been many hominid species living together at one time. New theories have been suggested since scientists revealed that the foot of a hominid found called the Burtele site was found ju...
Stringer, C. B. & Hublin, J-J. (1999). New age estimates for the Swanscombe hominid and their significance for human evolution. Journal of Human Evolution 37, 873–877.
Gibbons, Ann., 2002, One Scientists Quest for The Origin of our Species. Science, v. 298. http://rcp.missouri.edu/carolward/pdfs/quotebrunetpiece.pdf
The species A. afarensis is one of the better known australopithecines, with regards to the number of samples attributed to the species. From speculations about their close relatives, the gorilla and chimpanzee, A. afarensis’ probable social structure can be presumed. The species was named by Johanson and Taieb in 1973. This discovery of a skeleton lead to a heated debate over the validity of the species. The species eventually was accepted by most researchers as a new species of australopithecine and a likely candidate for a human ancestor.
read for my book report. Roger Lewin is a British award-winning science author and writer of 20 books. He was employed at New Scientist in London for about nine years. He went to Washington, D.C. to write books and other pieces for science for ten years as news editor. The book by him that I chose, in 201 pages, this book explained answers to questions like where and when modern humans first appeared, what features distinguish modern humans, who our immediate ancestors were, and many more. For example, the subtopics are; the African origin, the multiregional origin, the archeology of modern humans, language and modern human origins, symbolism and images, mitochondrial divergence, human variation, and an overview of homosapieans and the modern debate. In this book there are two main views in paleoanthropology, the study of humankind, about the origin of modern humans: the African origin and the multiregional origin.
Wilford, John Noble. "Homo Naledi, New Species in Human Lineage, Is Found in South African Cave." The New York Times. The New York Times, 10 Sept. 2015. Web. 08 Dec. 2015.
Scientists thought that interbreeding would be a logical assumption to the Neanderthal conundrum. Unfortunately, any evidence of DNA from Neanderthals mixed with human DNA is difficult to come by because their fossils are usually tarnished upon finding. That is until Svante Paabo, and his research team from the Max Planck Institute for Evolutionary Anthropology, came across the remains of twenty-four Neanderthals and forty early humans.* All of these fossils were nearly 40,000 years old and were from Germany, Russia, and Croatia. Nine of these fossils (four Neanderthal and five human)
2004 Has the Comination of Genetic and Fossil Evidence Solved the Riddle of Modern Humans?, Evolutionary Anthropology 13: 145-159.
The author has reviewed the previous studies on the barriers of regular physical activity in the community living older people (Jones and Nies 1996, Conn 1998, Heesch et al 2003, Lin et.al 2007). But the review shows that little study was done among older adults living in LTC about the barriers they face in their physical activity. The areas of nursing practices are to identify the barriers in older people that keep them away from their physical activity. Developing a plan of care and interventions depend on the individual problems.