martes, 6 de julio de 2010
Neanderthal Males Had 'Popeye'-Like Arms?
Remains of an early Neanderthal with a super strong arm suggest that Neanderthal fellows were heavily pumped up on male hormones, possessing a hormonal status unlike anything that exists in humans today, according to a recent paper.
Neanderthal males probably evolved their ultra macho ways due to lifestyle, genes, climate and diet factors, suggests the study, published in the journal Archaeology, Ethnology & Anthropology of Eurasia.
Project leader Maria Mednikova told Discovery News that Neanderthal males hunted in the "extreme," helping to beef up one arm.
"The common method for killing animals was direct contact with the victim," said Mednikova, a professor in the Institute of Archaeology at the Russian Academy of Sciences.
Instead of shooting prey, such as mammoths, with a bow and arrow from a distance, Neanderthal males would engage in face-to-face contact, jabbing long, thick spears directly into the animal's flesh.
Neanderthal females weren't delicate creatures either.
Mednikova and her colleagues believe that "compared to anatomically modern humans, (both male and female Neanderthals) had a larger muscle mass and experienced a higher loading on the upper extremity than did Homo sapiens." Also, "they differed from modern humans by a greater functional difference between the sexes in the use of the right arm."
Neanderthal males had Popeye-type right arms, while Neanderthal females had arms that were more evenly matched and not nearly as muscular.
Mednikova and her team analyzed a fossil humerus (long bone that extends from the shoulder to the elbow) for what they believe was an Neanderthal male that might have lived around 100,000 years ago in what is now Khvalynsk, Russia. The bone was put through computerized tomography, X-rays and other analysis.
The fossil displays an unusual mixture of thickened walls with narrow bone marrow region cavities. This, according to the scientists, suggests "intense mineralization" provided for the strong, sturdy bone structure, with the inner narrowness "based on a stronger shaft architecture requiring much less mineralization."
The mixture is puzzling, because "Neanderthals demonstrate a markedly androgenic constitution," meaning they seemed to have a lot of steroids, yet these same hormones can cause reduced mineralization.
As a result, the researchers say "Neanderthals were characterized not only by peculiar biomechanical adaptations, but also by a specific hormonal condition which has no close parallels among modern human hormonal conditions either normal or pathological."
This condition might have evolved as a result of inherited genes, life in an often cold, northern climate, and an almost all-meat diet.
Mednikova and her colleagues explained that edible plants in colder regions were few and far between, and the vegetation period was short. With little fruit and vegetables, the Neanderthals became "specialized hunters who hunted terrestrial herbivores," such as mammoths and forest deer. Their diet then consisted "nearly exclusively of proteins and lipids," which must have affected their hormones and bones.