国产探花

Dr Stewart's technique – honed in collaboration with Professor Janet Montgomery at University of Durham and Professor Raquel Gerlach at the University of São Paulo - analyses a gender-varied protein (amelogenin) found in tooth enamel. This has now been used to confirm that a skull found by workmen in 1943 at the former Branston Gravel Pits in Staffordshire was from a woman in her mid-20s who lived almost a thousand years ago, whom researchers nicknamed 'Greta'.

Analysing tooth enamel proteins bypasses issues with gender identification using ancient DNA, which is often badly degraded and prone to cross contamination. Dr Stewart's new approach based on tooth enamel protein provides a clear confirmation of the sex of ancient remains without these DNA problems.

Other scientists came up with further information about when the woman had lived and what she ate. Testing by the Radiocarbon Accelerator Unit at Oxford University was combined with data from the Ancient Genomics Laboratory at Cambridge University's Francis Crick Institute to show that, rather than being approximately 10,000 years old as had first been believed in the 1940s, 'Greta' almost certainly lived between 1041 and 1163 AD.

Dr Nicolas Stewart

Photo of 'Greta' skull by David Adkins

Work by Professor Janet Montgomery and Dr. Joanna Moore at Durham, meanwhile, revealed that 'Greta' ate a diet of mainly plants, meat and milk, supplemented between the ages of six and 13 with marine protein such as fish and shellfish.

Once considered the oldest human remains found in the UK – an idea bolstered by the discovery of a mammoth tooth in the clay near her skull - 'Greta' vanished from view for four decades until she was rediscovered in storage at The Potteries Museum in Stoke by anthropologist David Adkins.

, a Senior Lecturer in the School of Applied Science at the 国产探花, said: “Sex estimation can be done by bone analysis and then confirmed using ancient DNA analysis - but this is dependent on the quality in preservation of the material. Tooth enamel, however, is the hardest tissue, and can preserve these proteins over thousands of years.

“We discovered that you can estimate sex from the most abundant protein found in tooth enamel: amelogenin. Amelogenin exists as two different forms, which vary according to the chromosome they originated from. Females only have what is known as the X isoform whereas males have both the X and Y isoforms.”