She wasn't faster than a speeding bullet, but new research seems to indicate that Lucy and other early known human ancestors walked with greater ease and efficiency than previously believed, despite their short legs.
Conventional thought among paleoanthropologists has been that the short-legged australopithecines, such as Lucy, were primitive or ape-like and hominids developed long legs because they are characteristic of efficient bipeds. Not so, says Patricia Kramer, a University of Washington doctoral candidate and lecturer in anthropology, who will present evidence Thursday morning at the annual meeting of the American Association of Physical Anthropology in Salt Lake City that "Lucy was beautifully equipped to deal with her world" 3.2 million years ago.
Lucy is the name given to the skeleton of a small female Australopithecus afarensis found by Donald Johanson in Ethiopia in 1974. The skeleton is about 40 percent complete, which is unusually rare among early human ancestors. Many species, including other australopithecines, are only represented by scant fossil remains.
Kramer, who is a registered civil engineer and worked at Boeing as a structural engineer, took a distinctly unconventional approach toward her research, which is the basis of her doctoral dissertation. She used standardized equations that can, for example, calculate if the cargo doors on an airliner close properly, fit into place correctly and wont break. But instead of solving engineering problems, she used them to explain the evolutionary record of early humans.
"The equations can predict how much energy is required for something to move in space," explains Kramer. "If you take them and develop models that take into account the different leg lengths for Lucy and modern humans and calculate the different levels of energy required for each, the result is a comparison of how much energy is required for Lucy and a modern human to move at any speed."