The downsides of human evolution
By Kate Lunau - Friday, February 15, 2013 - 0 Comments
Kate Lunau’s latest dispatch from the AAAS meeting
Kate Lunau is in Boston covering the 2013 annual meeting of the American Association for the Advancement of Science (AAAS), where some of the world’s finest brains and celebrities of science meet to mix, mingle, and share their latest and greatest ideas. On Feb. 14-18, she’ll give you a sneak peak into the current research—everything from dinosaurs to neutrinos, from stem cells to extreme weather, and all sorts of sorts of stuff in between. Follow her on Twitter: @katelunau, #AAASmtg
In a talk this morning on human evolution, I kept imagining that classic diagram of an ape transitioning to an upright human—and how it should show him hunched over in back pain, hobbling on a twisted ankle, on his way to the dentist to get his wisdom teeth removed. Evolution has put us at the top of the food chain, but “evolution doesn’t produce perfection,” anthropologist Jeremy DeSilva said today at the AAAS Meeting, where he spoke on a panel with others. Adapting to bipedal walking has left us with all sorts of aches and pains that no other animals seem to suffer, everything from hernias and flat feet, to fallen pelvic floors. He called these adaptations the “biological equivalent of duct tape and paper clips,” which affect us everyday.
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New fossil discovery, new human?
By Jane Switzer - Wednesday, March 28, 2012 at 12:03 PM - 0 Comments
The hominid fragments differ greatly from modern humans but experts are reluctant to classify them as a new species
Peter Schouten
Fossils unearthed in southern China by a team of Australian and Chinese researchers may point to a new species in the human evolutionary tree. The partial skulls and bone fragments are believed to be between 14,500 and 11,500 years old, and do not closely resemble anatomically modern humans. The study by the researchers suggests that the potentially “late surviving archaic population,” named the Red Deer Cave people for their apparent love of venison, roamed alongside China’s earliest established people. Until now, no hominid fossils less than 100,000 years old have been found in mainland eastern Asia.
University of New South Wales evolutionary biologist Darren Curnoe, the study’s lead author, says the skulls have “a mosaic of archaic and modern” facial features and differ from modern humans in their jutting jaws, large molar teeth, prominent brows, thick skulls, flat faces and broad noses. “While finely balanced, I think the evidence is slightly weighted toward the Red Deer Cave people representing a new evolutionary line,” Curnoe told the Guardian. “They look very different to all modern humans, whether alive today or in Africa 150,000 years ago.”
But Curnoe is reluctant to classify the team’s finding as a new human species—and he isn’t alone. Other scientists have reacted critically to the study, published in the journal PLoS One. Even Curnoe admits there is a good reason: “In the science of human evolution or paleoanthropology, we presently don’t have a generally agreed, biological definition for our own species,” he told BBC News. Instead, the evidence may just tell us what we already know: humans are a very diverse species.
“I would be surprised if it really was a new human group that was previously undiscovered,” Philipp Gunz, a physical anthropologist at the Max Planck Institute for Evolutionary Anthropology in Germany, told National Geographic’s website. “Modern humans are exceptionally variable, especially if you compare modern humans to our closest fossil relatives, the Neanderthals.” Still, Homo sapiens or not, the Red Deer discovery “indicates that the evolutionary history of humans in East Asia is more complex than has been understood until now,” the study claims. So far, attempts to extract DNA from the fossils have been unsuccessful.
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Evolution favours shorter and heavier women—like it or not
By Katie Engelhart - Thursday, March 18, 2010 at 12:00 PM - 72 Comments
Natural selection is still at work
Photograph by Hans Neleman/ Getty
What might our granddaughter’s granddaughter’s granddaughter’s granddaughter’s granddaughter look like? Shorter and stouter, says a report in the Proceedings of the National Academy of Sciences. If current trends continue, its authors predict, then by 2409 descendants of the women in the study will have evolved to be one kilogram heavier and two centimetres shorter than their 2010 foremothers.
For years, some scientists heralded the end of human evolution. The post-industrial homo sapiens, they argued, was free of the kinds of “survival-of-the-fittest” pressures that could drive large-scale genetic change. In 2008, Steve Jones, professor of genetics at University College London, gave a much-hyped lecture entitled “Human Evolution is Over.” “Not so,” says Stephen Stearns, co-author of this latest study, professor of evolutionary biology at Yale University, and founding editor of the Journal of Evolutionary Biology. “The basic take-home is that humans continue to evolve,” Stearns told Maclean’s.
“One [could express] the result as: women are going to get shorter and fatter,” he explains. But he prefers a different bent: “There is natural selection against women being slender.” Stearns’s work shows that plumper, shorter women tend to bear more children—who carry on those same traits. His analysis drew on data from the Framingham Heart Study: a survey, begun in 1948, that collected medical information from 5,209 subjects, and monitored them and their offspring for 60 years.
