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n
the beginning, or so the story goes, an enlightened member of the primate
species Australopithecus afarensis gradually came to see the advantage
of standing on her own two feet. Tentative steps followed, and then, over
time, the creature and her cohort found themselves tottering about the
Pliocene-era grasslands of eastern Africa. Members of this particular
group of hominids— the term describes all bipedal primates, both
extant and extinct — have for the past quarter century been thought
to represent a direct evolutionary line back to the dawn of humankind.
No longer. A fossilized skull found near Kenya's Lake Turkana has shaken humanity's family tree to the roots, suggesting that at least two lines of potential human ancestors may have roamed the East African plains simultaneously. Even in a scientific field accustomed to a degree of uncertainty and guesswork, the revelation was stunning; a harsh reality check against what one scientist described as "our smug certainties about the past." Carol V. Ward, an associate professor of anthropology at MU, is among the handful of hominid specialists wrestling with the implications of the Lake Turkana fossils. Ward admits to no false certainties, smug or otherwise. In a field where almost every piece of evidence emerges as though by miracle, she says, even fossils that underscore our ignorance are welcome.
"We can speculate all we want about where we came from, but this is hard evidence," Ward says. Hard as a rock, in fact, which helps explain its elusiveness. "The odds that an early hominid would die and get buried without first being scavenged and eaten by animals — and the bones chewed up — are long," Ward says. "But add to that the chance that it would be buried in the right chemical environment to turn into rock and be preserved, then erode out again and be found and identified by an anthropologist . . . I've heard the odds are something like one in 10 billion. The fact that we get anything is absolutely amazing."
photo by Steve Morse
from Illumination
- Research, Scholarship and Creative Achievement
at the University of Missouri-Columbia
Fall 2001
published by the MU Office
of Research
Carol Ward links page Old Bones article beginning article page 2 article page 3 article page 4