Ancient Teeth Challenges Origins of Man

Most evidence for modern man is70,000 years or less.  Other evidencesuggests that the human form may well have been round for as much as 400,000years, except that evidence is not archeological and not accepted.

Besides all that, we have thereal problem of successful dispersion.  Asuccessful species can disperse in a rather short time period making itsfossils available throughout its full range at its moment of maximum success.  Yet every such success may have been adevelopment restricted to a small area for tens of millennia.

Imagine a successful tribal groupevolving for three hundred thousand years in Southern Africa, but making their living on the coast and never venturingnorth to contest the tropical mangroves. At some point they develop a tool kit that allows penetration of the interiorto hunt and settle.  From that moment onthey can settle the whole globe and they do so in mere thousand or so years.  This is a presently reasonable conjecture.

Thus ancient evidence is always greatlyinteresting, but should be understood as always tentative. 

Ancient teeth raise new questions about the origins of modern man

February 9, 2011

Teeth found at a site near Rosh Haain in Israel are providing newinformation about who the earlier occupants of this region were as well astheir potential evolutionary relationships with later fossils from this sameregion, says Binghamton University anthropologist Rolf Quam. Credit: Rolf Quam

Eight small teeth found in a cave near Rosh Haain, central Israel, are raising big questions about theearliest existence of humans and where we may have originated, says Binghamton University anthropologist Rolf Quam.Part of a team of international researchers led by Dr. Israel Hershovitz of TelAviv University, Qaum and his colleagues have been examining the dentaldiscovery and recently published their joint findings in the AmericanJournal of Physical Anthropology.

Excavated at Qesem cave, a pre-historic site that was uncovered in2000, the size and shape of the teeth are very similar to those of modern man,Homo sapiens, which have been found at other sites is Israel, such as Oafzehand Skhul - but they're a lot older than any previously discovered remains.

"The Qesem teeth come from a time period between 200,000 - 400,000years ago when human remains from the Middle Eastare very scarce," Quam said. "We have numerous remains of Neandertalsand Homo sapiens from more recent times, that is around 60,00 - 150,000 yearsago, but fossils from earlier time periods are rare. So these teeth areproviding us with some new information about who the earlier occupants of thisregion were as well as their potential evolutionaryrelationships with the later fossils from this same region."

The teeth also present new evidence as to where modern man might haveoriginated. Currently, anthropologists believe that modern humans andNeandertals shared a commonancestor who lived in Africa over700,000 years ago. Some of the descendants of this common ancestor migrated to Europe and developed into Neandertals. Another groupstayed in Africa and evolved into Homosapiens, who later migrated out of the continent. If the remains from Qesem canbe linked directly to the Homo sapiens species, it could mean that modern man eitheroriginated in what is now Israelor may have migrated from Africa far earlierthat is presently accepted.

But according to Quam, the verdict is still out as to what species isrepresented by these eight teeth, which poses somewhat of a challenge for anykind of positive identification.
"While a few of the teeth come from the same individual, most ofthem are isolated specimens," Quam said. "We know for sure that we'redealing with six individuals of differing ages. Two of the teeth are actuallydeciduous or 'milk' teeth, which means that these individuals were youngchildren. But the problem is that all the teeth are separate so it's beenreally hard to determine which species we're dealing with." 

 According to Quam, rather than rely on individual features,anthropologists use a combination of characteristics to get an accurate readingon species type. For instance, Neandertal teeth have relatively large incisorsand very distinctive molars and premolars whereas Homo sapiens teeth aresmaller with incisors that are straighter along the 'lip' side of the face.Sometimes the differences are subtle but it's these small changes that makehaving a number of teeth from the same individual that much more important.

But even though Quam and the team of researchers don't know for sureexactly who the teeth belong to, these dental 'records' are still telling thema lot about the past.

Lower premolars and canine teeth found at the Qesem cave site in Israel areraising new questions about the origins of modern man. If linked directly toHomo sapiens, it could mean that modern man either originated in what is nowIsrael or may have migrated from Africa far earlier that is presently accepted,says Binghamton University anthropologist Rolf Quam. Credit: Rolf Quam

"Teeth areevolutionarily very conservative structures," Quam said. "And so anydifferences in their features can provide us with all sorts of interestinginformation about an individual. It can tell us what they ate, what theirgrowth and development patterns looked like as well as what their generalhealth was like during their lifetime. They can also tell us about the evolutionaryrelationships between species, all of which adds to our knowledge of who we areand where we came from."

Excavation continues at the Qesem site under the direction of ProfessorAvi Gopher and Dr. Ran Barkai of Tel Aviv University.The archaeological material already recovered includes abundant stone tools andanimal remains, all of which are providing researchers with a very informative'picture' of daily life and hunting practices of the site's former inhabitants.

"This is a very exciting time for archeological discovery,"Quam said. "Our hope is that the continuing excavation at the site willresult in the discover of more complex remains which would help us pinpointexactly which species we are dealing with."

Quam continues to be in touch with the on-site archeologists and hopesto collaborate in the project when and if more complete human remains arerecovered.

Provided by Binghamton University

No comments:

Post a Comment