WeWuzHere

IF PRIZES were given for causing scientific headaches, Australia would be a gold medal winner every time.

Already palaeontologists have found evidence there that humans appear to be shrinking and that mankind in the antipodes developed from slim to robust forms, a reversal of the usual direction of recent human evolution.

But now researchers have gone even further. At Jimnium, in Australia's tropical north-west outback, they have found 76,000-year-old rock carvings and tools dated at around 176,000 years old.

These discoveries, if validated, mean the origins of art will have to be reconsidered, the abilities of our ancestor, Homo erectus, reappraised, and the birthplace of modem humans rethought - not bad going for a patch of grooves cut in a boulder.

The instigators of this latest bout of scientific trouble-making are Australian Museum and Wollongong University researchers, who have found thousands of dot-like indentations engraved on a group of monoliths. Some are 76,000 years old, it is claimed. In addition, stone tools reckoned to be between 116,000 and 176,000 years old have been discovered at the site.

'The initial samples were taken four to five years ago. We were so shocked with the results that we have been trying to go over them to disprove these things, and we can't do that,' said team leader Richard Fullagar yesterday.

The first discovery, of the grooves, overturns previous ideas about the date of art's first appearance. Until now the most ancient form was thought to be some 32,000 year-old cave paintings in France. But researchers always accepted the possibility of earlier works being found, and Australia had become a strong candidate for finds.

In recent years necklaces, engravings and red ochre (a body paint) have been found at Australian sites dated 30,000 years old. Such artefacts must have had artistic predecessors, so scientists are not too surprised that some may now have been found.

The problem is not the art but the date. Modern Homo sapiens, who emerged from Africa about 100,000 years ago, was not thought to have reached the continent � on primitive boats � until 50 to 60 thousand years ago.

Bringing forward that date by 15,000 years is painful, albeit non-fatal, for scientists' theories. But the discovery of far older stone tools and other artefacts in nearby soil sediments has set the cat among. the palaeontological pigeons.

If modern humans did not emerge from Africa until about 100,000 years ago, this only leaves our primitive predecessors, Homo erectus, as likely candidates to be the tools' makers ? even though they were never thought to have reached the antipodes.

Hormo erectus is supposed to have emerged from Africa a million years ago, but because these early men were not believed to have had the intellects to make boats, they were thought to have been confined to Europe, Asia and Africa.

This new Australian discovery challenges this notion at a time when our understanding of Homo erectus is already under reappraisal. Two years ago US scientists found evidence to suggest erectus had reached Asia not one million, but two million years ago ? the same time they first appeared in Africa.

As a result, some scientists now argue that erectus may actually have evolved in Asia, and that mankind's origins are not solely based in Africa. The discovery that our ancient ancestors may have reached Australia further undermines our understanding of this enigmatic species, and suggests we may need to rewrite our theories about them and ourselves.

On the other hand, the dating of the Jinmium tools may simply be incorrect, in which case existing evolutionary theory would remain intact.

As to Homo sapiens shrinking, first revealed in Australian skeletons, it is now accepted as a phenomenon linked to agriculture's emergence, which meant we no longer needed robust physiques for gathering food. ENDS