Tuesday, August 3, 2010

Researchers discover fossil of human older than Tabon Man

Move over, Tabon Man. Callao Man is here.

Evidence has emerged that the islands comprising the Philippines could have been inhabited by humans more than a dozen millennia before the so-called Tabon Man of Palawan, long thought to be the archipelago’s earliest human remains.

A team of archaeologists led by Dr. Armand Mijares of the University of the Philippines-Diliman has confirmed that a foot bone they discovered in Callao Cave in Cagayan province was at least 67,000 years old. Tabon Man’s remains were a relatively young 50,000 years old.

The foot bone discovered in Callao Cave was a mere 61 millimeters or 2.4 inches. Photo courtesy of Dr. Armand Mijares. “So far this could be the earliest human fossil found in the Asia-Pacific region. The presence of humans in Luzon shows these early humans already possess knowledge of seacraft-making in this early period," Mijares told GMANews.TV in an exclusive interview conducted by email in between archaeological digs.

Mijares acknowledged being “shocked and elated" at the discovery, adding that it was something people in his field dream of. “I am a Pleistocene Archaeologist and our efforts are meant to unravel the deep past," he said.

His team’s findings were recently published in the scholarly journal Human Evolution, but the actual discovery of the bone occurred in 2007. However, it was not clear then just how old the fossil was. Mijares said they were able to approximate its age through a method called “uranium-series dating."

The primary theory is that Callao Man, or his ancestors, reached Luzon from what is now Indonesia by raft at a time when experts did not think human beings were capable of traveling long distances by sea.

However, the scientists also found signs that Callao Man might not have been fully human, but only a species akin to modern man.

According to Dr. Victor Paz, a UP colleague of Mijares who was not part of the excavation, the bone could be evidence of human “speciation" taking place in Luzon. (Speciation is the evolutionary process by which new biological species arise.)

“If speciation did take place in the region and more evidence comes out of older modern human remains, it may seriously challenge current conventions on the spread of modern humans to our region," Paz said.

Based on the single bone, it is not clear that Callao Man was male. But they do know that its physical size was similar to the modern Negrito, or Aytas of Luzon. The bone was the third metatarsal of the foot, thus is referred to scientifically as Callao MT3.

Archaeologist Armand Mijares stands in excavation site in Callao Cave where he and his team discovered the earliest human fossil in the Philippines, and perhaps in all of the Asia-Pacific. Photo courtesy of Armand Mijares. The human bone was found in the town of Penafrancia, Cagayan in an excavation site where Mijares had started digging four years before.

“We were initially frustrated that during the excavation we were only finding animal remains. But when my colleague Dr. Phil Piper, our team’s zoo-archaeologist, was looking at the finds, he said to me, 'Mandy this is a human bone,'" Mijares said. “When we verified that it is a human bone, I knew that we discovered something very important."

The presence of the remains of butchered animals in the same layer of sediment, but no stone tools, raises interesting questions about how Callao Man killed them.

“We can only speculate that they were using different tools. From our initial analysis of the cut marks on the animal bones, they could have used organic tools such as bamboo which is ubiquitous in the region," Mijares said.

Where there is a single human bone there could be more, so Mijares and his team intend to continue digging. Additional discoveries of remains of Callao Man could be enough to show with more certainty that he was of an earlier species than homo sapiens, which could mean that the first modern humans in the archipelago did not sail here but evolved here.-GMANews.TV

* From YAHOO

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