Borrowed from The Bradshaw foundation, a site well worth several visits.
Dating the arrival of Anatomically Modern Humans in East Asia: Who made the Kota Tampan tools and when?
No one has done more research into Kota Tampan and the Lenggong Valley culture than archaeologist Zuraina Majid, of the Universiti Sains Malaysia in Penang. Her extensive work at a number of sites in the Lenggong Valley suggests that a local pebble-tool culture may have existed from the days of that great Toba volcanic eruption right up until 7,000 or even only 4,000 years ago. If that is so, it may provide the answer to one of the most nagging questions about the unifacial oval pebble tools: who made them? On the face of it, these are by no stretch of the imagination sophisticated tools. Better-looking tools were made long before in Africa and Europe by archaic humans, so why should anyone think that the unifacial pebbles encased in volcanic ash had been made by modern humans living at the time of Toba?
Two of the highest authorities on the Southeast Asian Palaeolithic, Australian archaeologists Peter Bellwood and Sandra Bowdler, agree with Zuraina Majid and Tom Harrison to the extent that these tools were most likely made by Anatomically Modern Humans. For a start, the dates for most of the pebble tools found in the Lenggong Valley are too recent for them to have been made by anyone else. Second, no pre-modern humans have ever been found in the Malay Peninsula, let alone in the Lenggong Valley.
Zuraina’s trump card in this respect is the much publicized finding by her team of ‘Perak Man’ in the Gunung Runtuh cave in the Lenggong Valley in 1990. Surrounded by the same class of pebble tools, this complete skeleton of a modern human was described by experts as having Australo-Melanesian characteristics. He was about 10,000 years old. This clear recent association of pebble tools with modern humans undermines the argument that the Kota Tampan pebble tools were too crude to be the work of moderns. The same locality also provides a continuity link with the older tools, which Zuraina argues is supported by technical comparisons. So, for the moment at least, Perak Man is the best local evidence that the older pebble tools encased in ash were made by the same (modern) human species.
Another venerable expert on the archaeology of Southeast Asia is Richard Shutler. He makes the more general point that these kinds of tools were first brought to Island Southeast Asia (meaning all the islands of Indonesia, Malaysia and the Philippines) by Homo sapiens about 70,000 years ago. Shutler cautions against the view that such tools reflect cultural backwardness, agreeing with others that the quality of the available raw material determined what could be used for tools, and that for more sophisticated implements such as knives, bamboo was more likely to have been used.
So how old was the Kota Tampan ash?
When it was first dated, several decades ago, the result came out at 31,000 years old. This date for ash from the Toba volcano has always worried geologists, and even archaeologists such as Peter Bellwood. The trouble is that Toba did not undergo a massive explosion at that time. Toba’s last big bang, the largest explosion in the world in the past 2 million years, came much earlier, 71,000–74,000 years ago. More recently several geologists, including the one who did the original dating, have agreed that the ash surrounding the tools was indeed 74,000 years old. The dating is critical. If the Kota Tampan pebble tools were made by modern humans, they would be the oldest precisely dated evidence for modern humans outside Africa. It therefore looks as though the ancestors of the Australians could well have left Africa and arrived in Malaysia on their beachcombing trail before the great Toba explosion.
Another piece of evidence from the region may help place Anatomically Modern Humans in the Far East over 70,000 years ago. This is the famous southern Chinese Liujiang skeleton. Consisting of a well-preserved skull and a few other bones, Liujiang was discovered in a small cave at Tongtianyan in the Guangxi Zhuang Autonomous Region in 1958 by people collecting fertilizer. There is no doubt that this person was anatomically modern, but from the start there has been controversy over its age.
A uranium date of 67,000 years was reported, but has been questioned on the basis of its exact location in relation to dated geological strata. In December 2002, a Chinese group headed by geologist Shen Guanjun reported their reinvestigation of the stratigraphy of the cave and dating of the skull (extending to several neighbouring caves) and claim it should be placed in a time bracket between 70,000 and 130,000, and not less than 68,000, years ago. The skull was found in a so-called intrusive breccia, a secondary flow of debris containing jumbled material of different ages. From their paper in the prestigious Journal of Human Evolution, the lower date bracket of 68,000 years seems solid, since it comes from multiple date estimates of the flowstone above and covering the breccia. (A flowstone forms when flowing water deposits calcite down a wall or across a floor.) Their preferred dating of 111,000–139,000 years ago based on unstratified fragments of flowstone and calcite within the breccia seems more speculative.
I have stuck my neck out to place modern humans in Malaysia by this date on the basis of the Kota Tampan site where tools were found under a thick layer of volcanic ash from Toba. The key tools were indisputably artefacts, and the ash did come straight from the sky 74,000 years ago. But in spite of majority view that the Kota Tampan tools were the handiwork of modern humans, they could still theoretically have been made by other humans, since no bones have been found on-site which would confirm the identity of their makers. The only modern human remains of that antiquity found in the region are the now re-dated Liujiang skull and partial skeleton from southern China. The dating of the earliest Flores (Eastern Indonesia) occupation by modern humans remains to be published. I have several corroborating reasons for relying on such a connection. First of all, the logic of the low-water colonization of Australia 65,000 years ago fits; and second, increasing numbers of genetic dates outside Africa easily reach back to this time. The next available low-water slot for the colonization of Australia would have been around 50,000 years ago, but that does not fit the other evidence so well.