A team of Australian archaeologists have sparked an academic row by claiming to have solved the riddle of a missing 1,000 years in human prehistory. The scientists from Melbourne's La Trobe University have found remnants of grains on the shore of the Dead Sea in Jordan that they believe help fill the 1,000-year gap in our knowledge of man's transition from nomad to farmer. But not everyone agrees, and the Australian team is now muscling up for an academic arm wrestle next month with the exponents of different theories in France. The debate is all about the period when man shifted from being a nomadic hunter-gatherer to settling down as a sedentary farmer. Conventional wisdom is that the transitional period, known as the Pre-Pottery Neolithic A (PPNA) period, finished about 9,200 BC. But La Trobe's Archaeology Program Coordinator Dr Phillip Edwards says the university's discovery of wild ancestors to domestic crops in Jordan now proves the PPNA in fact lasted until 8,300 BC.