By Adam Dubbin
TheSequitur.com Contributor   
March 31, 2006
[Image - Futura Sciences]

GAINESVILLE, Fla. -- The skull of one of the earliest ancestors of man was found in Gawis, northeastern Ethiopia, a hot-bed of archaeological evidence.

The Associated Press and Reuters reported that the cranium discovered Feb. 16, 2006 is estimated to be between 200,000 to 500,000 years old – placing the find during an era known as the middle Pleistocene.  Some rudimentary tools and “fossilized animals” were also found in the same trench.

The area where the find was made is the same place where U.S. anthropologist Donald Johnson made his remarkable discovery in 1974 of a skeleton estimated to be 3.2 million years old.  These remains are famously known as ‘Lucy’ (Australopithicus afarensis).  This discovery gave credence to the ‘Out of Africa’ theory of human expansion, muffling the voices of those who postulated that humans co-evolved in different regions of the world.  The evidence, however, is not overwhelming and there remains much debate as to whether humans originated in Africa alone.

That dispute echoes in the talk surrounding the bones and whether or not they belong to a common human ancestor, or just a distant cousin.  Sileshi Semaw, an Ethiopian paleoanthropologist responsible for the discovery, noted that the skull appeared “to be intermediate between the earlier Homo erectus and the later Homo sapiens,” according to Reuters.  Michael J. Rogers, a professor of anthropology at Southern Connecticut State University said that it’s “the most significant fossil he’s ever seen,” according to the AP.  The skull was recovered almost completely intact, a very rare event for crania of early hominids.  Because of that, Semaw was able to detect similarities in the morphology of the skull and that of modern humans, despite obvious differences.

Beyond the uncertainty, this skull could potentially be a Rosetta stone for paleoanthropologists.  Hailed as a possible ‘missing link,’ such intact finds can help anthropologists conceptualize the human family tree.  Cranium volumetric studies can provide excellent evidence for brain size comparisons; the analysis of facial bones and their articulations can also elucidate questions about how man came to be.  Because there are other intermediary species of human phylogeny that we know of, such as Homo habilis, scientists should be able to determine the skull’s location on the family tree.

The presence of tools and animals remains in the vicinity should also help clarify our understanding of early hominids.  Tool-making is a trademark skill employed by animals with opposable thumbs- a feature novel to the human family.  The animal remains can be investigated for evidence of hunting or butchering, as well as char-marks from cooking.

When one considers the many different lineages of hominids, as shown in the fossil record, it almost invokes an image of an environment roaming with scrawny, bipedal scavengers of all sorts, just as the apes now roam central Africa.  But in reality, these different genera and species came to exist over hundreds of thousands of years, with only a few of them likely overlapping.

Researchers still plan on dating the remains to a more precise date using potassium to argon isotope ratio.  It is not likely that the current age estimates were extrapolated from stratigraphic data, since the skull was found on an ‘archaeological reconnaissance survey’, as opposed to a dig trench.  Also, more morphological comparisons need to be undertaken before any concrete conclusions can be drawn on the skull and possibly biochemical analysis of the tools to further understand their relationship.

In the meantime, we can all sit and speculate on the origins of our species and learn more about the fantastic beast: Homo sapiens.
[AP, Reuters, Record-Journal]