Hobbit fuss goes out on some limbs: debate over pint-sized fossils turns to arm and leg bones.
ALBUQUERQUE -- Two fossil "hobbits" have given what's left of their arms and legs to science.
But that wasn't enough to quell debate over hobbits' evolutionary status at the annual meeting of the American Association of Physical Anthropologists.
Since 2004, the discoverers of these unusual fossils on the Indonesian island of Flores have attributed their find to an ancient pint-sized hominid, Homo floresiensis, that survived there until 17,000 years ago--a shockingly recent date in human evolutionary terms.
Critics say the finds represent nothing more than human pygmies like those still living on Flores. If so, the centerpiece hobbit find--a partial female skeleton known as LB1--is what's left of a woman who suffered from a developmental disorder that resulted in an unusually small body and brain.
But arm and leg bones from LB1 and another hobbit appear healthy, concludes a study led by William Jungers of Stony Brook University in New York. The bones display normal thickness in the tissue that forms the outer shell of most bones, as well as symmetry that signals healthy growth, said Stony Brook anthropologist and study coauthor Frederick Grine, who presented Jungers' paper on April 17.
The scientists also found that H. floresiensis limb strength rivals that estimated for ancient hominids such as the 3.2-million-year-old Australopithecus afarensis, a.k.a. Lucy. That suggests hobbits could engage in arboreal acrobatics and other vigorous activities that humans generally can't manage. Hobbits may have spent much time climbing trees, as Lucy's kind did, the researchers propose.
In a separate presentation, Robert Eckhardt of Pennsylvania State University in University Park conjured an entirely different animal from the very same bones. He argued that a developmental disorder produced a suite of skeletal abnormalities in LB1 (SN: 11/18/06, p. 330), including irregularly shaped hip joints and tube-shaped upper leg bones.
A variety of developmental disorders produce skeletal traits in people today that Jungers has labeled as exclusive to H. floresiensis, Eckhardt argued. He described the case of a woman with a developmental disorder that resulted in an S-shaped collar bone, which Jungers' team lists as a hobbit-specific feature.
This new twist in the hobbit controversy follows the March 17 online publication of a paper in Nature concluding that hominids reached Flores before 1 million years ago. Excavations on Flores yielded stone tools from sediment dating to that time, reported Adam Brumm of the University of Wollongong in Australia.
Brumm's contention has been challenged by colleagues who believe natural processes may have moved the artifacts from younger to older sediment layers.
|Printer friendly Cite/link Email Feedback|
|Date:||May 8, 2010|
|Previous Article:||Eating seaweed gives gut a boost: bacteria enable some Japanese to digest the indigestible.|
|Next Article:||Hominid species named.|