Homo habilis

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  • Publicado : 13 de marzo de 2012
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health data that belong in the public domain.” Widespread worry about the fertility of Danish men is another reason the board felt justified in its actions, according to Saugmann-Jensen. “We had concerns about a negative stamp being put on a whole generation of men,” he says, pointing to an article from Slate.com last year with the title “The Little Princes of Denmark. Why do Daneshave smaller nuts than Finns—are toxins to blame?” The board “felt there was a mismatch between the public perception that there is an ongoing deterioration in young men’s reproductive potential and the fact that no change in sperm numbers had occurred over many years of state-of-the-art surveillance,” he says. The report specifically addresses the media’s role in reporting scientific findings onthe topic, urging reporters and the public to remember that “statements from researchers or research groups are usually not synonymous with scientific finality.” Saugmann-Jensen says the agency did not deliberately court media attention for the report, however. He says a journalist who had heard about the report contacted him, and he was happy to answer questions. Skakkebaek says he and Jørgensendid ask the Board of Health to remove the online report, in part because they disagree with the

conclusions drawn from their data. They concur there is no decrease in sperm count over the 15-year period, but they say that the overall levels are worryingly low. The Board of Health’s report plays down that concern, saying it is impossible to draw clearconclusions about what a “low” sperm count is. Danish sperm counts are similar to those observed in

“We are moving as a society ty toward the idea of data not being the property of the people who collect it.”

German and Norwegian men, it notes. The authors of the Epidemiology commentary commissioned by Wilcox, who call the data “the best longitudinal semen datayet available,” share some of Jørgensen and Skakkebaek’s concern. “The proportion of young men with low sperm counts is surprisingly large,” they write. “It is somehow hard to think it has always been so.” They conclude that further examination of possible causes— whether environmental exposures, obesity, or


Who Was Homo habilis—And Was It Really Homo?
Ever since he receiveda cryptic telegram in 1959, Phillip Tobias has pondered the identity of a certain human ancestor. The telegram came from his colleagues Louis and Mary Leakey in Kenya. “We’ve found the man,” it said. “Come quickly.” As soon as he could book a flight, Tobias rushed from Johannesburg, South Africa, to Nairobi to examine the partial skull, teeth, and hand and foot bones of several individuals thatthe Leakey team had found in Olduvai Gorge, Tanzania. Because the fossils were found near stone tools, Tobias and the Leakeys named the new hominin Homo habilis, or “handy man.” As new H. habilis fossils emerged over the decades, the researchers and others came to consider the species the first member of our own genus, a crucial ancestor that gave rise to H. erectus in an unbroken lineage that ledto us. But in the past decade, the handyman’s status has been undermined. Newer analytical methods suggested that H. habilis matured and moved less like a human and more like an australopithecine, such as the famous partial skeleton of Lucy. Now, a

Homo habilis

Homo erectus

Food processors. Microscopic images show pits and diverse patterns of wear on two H. erectus teeth (right), ascompared with H. habilis teeth, suggesting that H. erectus individuals ate a broader range of tough foods that gouged their teeth.

report in press in the Journal of Human Evolution finds that H. habilis’s dietary range was also more like Lucy’s than that of H. erectus, which many consider the first fully human species to walk the earth. That suggests the handyman had yet to make the key adaptations...
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