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Recommended for: Grades 9-12

Resource: The Transforming Leap, from Four Legs to Two

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John Noble Wilford, a New York Times science writer, outlines various hypotheses on the origin of bipedalism.

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Teachers' Domain, The Transforming Leap, from Four Legs to Two, published September 26, 2003, retrieved on ,
http://www.teachersdomain.org/resource/tdc02.sci.life.evo.transleap/

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Excerpted from The Science Times Book of Fossils and Evolution, edited by Nicholas Wade, this article outlines the major hypotheses, past and present, that attempt to explain the evolution of bipedal walking in human beings. From environmental to social/behavioral change, many factors may have influenced our early ancestors. John Noble Wilford outlines scientists' various arguments and counter arguments.