Million-year-old skull rewrites human evolution, scientists claim 59 minutes ago Share Save please log in to view this image Pallab GhoshScience Correspondent please log in to view this image BBC News Replica: the skull is a million years old but has some modern features A million-year-old human skull found in China suggests that our species, Homo sapiens, began to emerge at least half a million years earlier than we thought, researchers are claiming in a new study. It also shows that we co-existed with other sister species, including neanderthals, for much longer than we've come to believe, they say. The scientists claim their analysis "totally changes" our understanding of human evolution and, if correct, it would certainly rewrite a key early chapter in our history. But other experts in a field where disagreement over our emergence on the planet is rife, say that the new study's conclusions are plausible but far from certain. The discovery, published in one if the world's leading scientific journals, Science, shocked the research team, which included scientists from a university in China and the UK's Natural History Museum. "From the very beginning, when we got the result, we thought it was unbelievable. How could that be so deep into the past?" said Prof Xijun Ni of Fudan University, who co-led the analysis. "But we tested it again and again to test all the models, use all the methods, and we are now confident about the result, and we're actually very excited." please log in to view this image Fudan University The skulls were discovered by a Chinese team in Hubei Province in central China who compared them with other human species When scientists found the skull, named Yunxian 2, they assumed it belonged to an earlier ancestor of ours, Homo erectus, the first large-brained humans. That's because it dated back about a million years, long before more advanced humans were thought to have emerged. Homo erectus eventually evolved and began to diverge 600,000 years ago into Neanderthals and our species – Homo sapiens. But the new analysis of Yunxian 2, which has been reviewed by experts independent of the research team, suggests that it is not Homo erectus. It is now thought to be an early version of Homo longi, a sister species at similar levels of development to neanderthals and Homo sapiens. Genetic evidence suggests it existed alongside them, so if Yunxian 2 walked the Earth a million years ago, say the scientists, early versions of neanderthal and our own species probably did too. This startling analysis has dramatically shifted the timeline of the evolution of large-brained humans back by at least half a million years, according to Prof Chris Stringer of the Natural History Museum, a co-lead on the research. He said there are likely to be million year-old fossils of Homo sapiens somewhere on our planet - we just haven't found them yet. please log in to view this image 0:45 Watch Science Correspondent Pallab Ghosh explain how the human family tree may have been redrawn There are two ways to pinpoint the species of an early human and work out when it walked the Earth - analysing the shape of the skull and its genetic data. In the case of Yunxian 2 both methods were used, and each came to the same conclusion. But other researchers, such as Dr Aylwyn Scally, an evolutionary geneticist at Cambridge University, say there are considerable uncertainties in both methods. "One has to be particularly tentative about the the timing estimates, because those are very difficult to do, regardless of what evidence you're looking at, be that genetic or fossil evidence," he said. "Even with the largest amount of genetic data, it is very difficult to place a time when these populations may have coexisted to within 100,000 years, or or even more." He added that while Profs Ni and Stringer's conclusions were plausible, they were far from certain, and that more evidence was needed to be sure. "That picture is still quite unclear to us, so if the conclusions of this research are supported by other analyses, ideally from some genetic data, then I think we would start to be increasingly confident about it," he told BBC News. The earliest known evidence for early Homo sapiens in Africa is 300,000 years ago, so it is tempting to conclude that our species might have evolved first in Asia. But there is not enough evidence to be sure at this stage, according to Prof Stringer, because there are human fossils in Africa and Europe that are also a million years old that need to be incorporated into the analysis. "There is some genetic evidence that points to the even earlier emergence of our species which may have recombined with our lineage, but this is not yet proven," he told BBC News. The earlier timeline means that the three species of humans co-existed on the planet for around 800,000 years, much longer than previously thought, perhaps interacting and interbreeding in that time. please log in to view this image Fudan University The white skulls are the orginal, distorted fossils and the grey ones are replica's that have been computer corrected The earlier emergence also helps make sense of dozens of human fossil remains dating from 800,000 years ago and 100,000 years ago that scientists have found hard to classify and find their place in the human family tree – the so-called "muddle in the middle". But the earlier emergence of Homo sapiens, Homo longi and Neanderthals neatly solves the problem. It means that is now possible to group the hard-to-classify fossils as subgroups belonging to one of the "big three," or their more primitive ancestors, Asian Homo erectus and heidelbergensis, according to Prof Ni. "Human evolution is like a tree," he said. "This tree included several branches, and there were three major branches that are closely related, and they may have some interbreeding to each other, and they coexisted for almost 1 million years. So this is an unbelievable result." The skull was excavated along with two others from Hubei Province. But they were damaged and crushed, which is one of the reasons that Yunxian 2 had been miscategorised as erectus. To restore them to their original shape, Prof Ni's team scanned the skulls and undistorted them using computer modelling techniques and then printed replicas on a 3D printer. Seeing them as they truly were enabled the scientists to reclassify them as a separate – more advanced group of human.
“The earlier timeline means that the three species of humans co-existed on the planet for around 800,000 years, much longer than previously thought, perhaps interacting and interbreeding in that time.” Must have found their way to Norwich too then!
Life-changing eye implant helps blind patients read again please log in to view this image 0:40 Sheila Irvine, who is registered blind, punches the air with joy at being able to read again A group of blind patients can now read again after being fitted with a life-changing implant at the back of the eye. A surgeon who inserted the microchips in five patients at Moorfields Eye Hospital in London says the results of the international trial are "astounding". Sheila Irvine, 70, who is registered blind, told the BBC it was "out of this world" to be able to read and do crosswords again. "It's beautiful, wonderful. It gives me such pleasure." The technology offers hope to people with an advanced form of dry age-related macular degeneration (AMD), called geographic atrophy (GA), which affects more than 250,000 people in the UK and five million worldwide. In those with the condition - which is more common in older people - cells in a tiny area of the retina at the back of the eye gradually become damaged and die, resulting in blurred or distorted central vision. Colour and fine detail are often lost. The new procedure involves inserting a tiny 2mm-square photovoltaic microchip, with the thickness of a human hair, under the retina. Patients then put on glasses with a built-in video camera. The camera sends an infrared beam of video images to the implant at the back of the eye, which sends them on to a small pocket processor to be enhanced and made clearer. The images are then sent back to the patient's brain, via the implant and optic nerve, giving them some vision again. The patients spent months learning how to interpret the images. Mahi Muqit, consultant ophthalmic surgeon at Moorfields Eye Hospital in London, who led the UK arm of the trial, told the BBC it was "pioneering and life-changing technology". "This is the first implant that's been demonstrated to give patients meaningful vision that they can use in their daily life, such as reading, writing. "I think this is a major advance," he said. How the implant technology works For the research, published in the New England Journal of Medicine, 38 patients with geographic atrophy in five European countries took part in the trial of the Prima implant, which is made by California biotech Science Corporation. Of 32 patients given the implant, 27 were able to read again using their central vision. After a year, this equated to an improvement of 25 letters, or five lines, on an eye chart. For Sheila, from Wiltshire, the improvement is even more dramatic. Without the implant, she is completely unable to read. But when we filmed Sheila reading an eye chart at Moorfields Hospital, she did not make a single error. After completing it, she punched the air and cheered. 'I am one happy bunny' please log in to view this image Sheila says she rushes her chores every day in order to sit down and put on the special glasses The task took huge concentration. Sheila had to put a pillow under her chin in order to steady the feed from the camera, which can focus on just one or two letters at a time. At some points she needed the device switched to magnification mode, especially to distinguish between the letters C and O. Sheila began losing her central vision more than 30 years ago, due to loss of cells in the retina. She describes her vision as like having two black discs in each eye. Sheila gets around using a white cane because her very limited peripheral vision is completely blurred. She is unable to read even the largest street signs when outdoors. When she had to give up her driving licence, she says she cried. But after having an implant fitted around three years ago, she is delighted by her progress, as is the medical team at Moorfields. "I am able to read my post, books, and do crosswords and Sudoku," she says. When asked if she ever thought she'd read again, Sheila replied: "Not on your nelly!" "It is amazing. I am one happy bunny," she adds. "Technology is moving so fast, it's amazing that I am part of it." please log in to view this image Sheila concentrates hard in order to read Sheila doesn't wear the device when outdoors. In part, this is because it requires great concentration - her head has to be held very still in order to read. She also does not want to become over-reliant on the device. Instead, she says she "rushes her chores" at home each day before sitting down and putting on the special glasses. The Prima implant is not yet licensed so is not available outside of clinical trials, and it's unclear how much it may eventually cost. Nonetheless, Mahi Muqit said he hoped it would be available to some NHS patients "within a few years." It's possible the technology could be used to help people with other eye conditions in the future. Dr Peter Bloomfield, director of research at Macular Society, says the results are "encouraging" and "fantastic news" for those who currently have no treatment options. "Artificial vision may offer a lot of hope to many, particularly after previous disappointments in the world of dry AMD treatment. "We are now watching closely to see if the Prima implant will be approved for use here in the UK, and crucially whether it could be made available on the NHS." The implant would not help restore sight in people born blind, because they don't have a functioning optic nerve to pass signals to the brain.
