A Closer Look at Lucy: Sexual Dimorphism and Speciation in Australopit

A Closer Look at Lucy: Sexual Dimorphism and Speciation in Australopithecus In his peer-reviewed article, â€Å"Sexing fossils: a boy named Lucy?,† James Shreeve discusses, in detail, a study on sexual dimorphism and possible speciation in Australopithecines in Hadar, Ethiopia, based on the famous A. afarensis specimen, â€Å"Lucy.† In the article, â€Å"Lucy’s kind takes humanlike turn,† the author addresses sexual dimorphism and speculates on sex-based differences in behaviors in A. afarensis. The two articles have differences and commonalities with each other in content and both present research methods and conclusions on topics including sexual dimorphism, sex-based behaviors, and speciation in Australopithecines, which receive critical analysis. 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, â€Å"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. Hausler and Schmid suggest that speciation exists within the Hadar Australopithecines – that the specimens represent not just one species (afarensis), but two. To support their view, the scientists use calculations showing the sexual dimorphism (the presence of characteristics that differ between male and female members) among Australopithecines. Again, by studying sexual dimorphic traits, the scientists claim that â€Å"Lucy† is possibly male, not fema... ...â€Å"Sexing fossils: a boy named Lucy?,† a peer-reviewed article by James Shreeve, and the article â€Å"Lucy’s kind takes humanlike turn† address subjects including sexual dimorphism, sex-based behaviors, and speciation of Australopithecines. While the two articles differ in the research and findings presented, they share a main, significant conclusion about Australopithecines, which is the sexual dimorphism in body size. Male A. afarensis are evidently larger than females, although there is some disagreement as to how much larger (the degree of sexual dimorphism). Works Cited B.B. (2003). Lucy’s kind takes humanlike turn. Science News, 164, 3, p45(1). Retrieved April 5, 2004 from Infotrac Onefile database. Shreeve, James. (1995). Sexing fossils: a boy named Lucy? Science, 270, 5240, p1297(2). Retrieved April 5, 2004 from Infotrac Onefile database.