科学家发现非洲以外人类最古老的脚印遗迹

Scientists have discovered the earliest evidence of human footprints outside of Africa, on the Norfolk Coast in the East of England.

The footprints are more than 800,000 years old and were found on the shores of Happisburgh.

They are direct evidence of the earliest known humans in northern Europe.

Details of the extraordinary markings have been published in the science journal Plos One.

The footprints have been described as "one of the most important discoveries, if not the most important discovery that has been made on [Britain's] shores," by Dr Nick Ashton of the British Museum.

"It will rewrite our understanding of the early human occupation of Britain and indeed of Europe," he told BBC News.

The markings were first indentified in May last year during a low tide. Rough seas had eroded the sandy beach to reveal a series of elongated hollows.

I walked with Dr Ashton along the shore where the discovery was made. He recalled how he and a colleague stumbled across the hollows: "At the time, I wondered 'could these really be the case? If it was the case, these could be the earliest footprints outside Africa and that would be absolutely incredible."

Such discoveries are very rare. The Happisburgh footprints are the only ones of this age in Europe and there are only three other sets that are older, all of which are in Africa.

"At first, we weren't sure what we were seeing," Dr Ashton told me, "but it was soon clear that the hollows resembled human footprints."

The hollows were washed away not long after they were identified. The team were, however, able to capture the footprints on video that will be shown at an exhibition at London's Natural History Museum later this month.

The video shows the researchers on their hands and knees in cold, driving rain, engaged in a race against time to record the hollows. Dr Ashton recalls how they scooped out rainwater from the footprints so that they could be photographed. "But the rain was filling the hollows as quickly as we could empty them," he told me.

The team took a 3D scan of the footprints over the following two weeks. A detailed analysis of these images by Dr Isabelle De Groote of Liverpool John Moores University confirmed that the hollows were indeed human footprints, possibly of five people, one adult male and some children.

Dr De Groote said she could make out the heel, arch and even toes in some of the prints, the largest of which would have filled a UK shoe size 8 (European size 42; American size 9) .

"When I was told about the footprints, I was absolutely stunned," Dr De Groote told BBC News.

"They appear to have been made by one adult male who was about 5ft 9in (175cm) tall and the shortest was about 3ft. The other larger footprints could come from young adult males or have been left by females. The glimpse of the past that we are seeing is that we have a family group moving together across the landscape."

It is unclear who these humans were. One suggestion is that they were a species called Homo antecessor, which was known to have lived in southern Europe. It is thought that these people could have made their way to what is now Norfolk across a strip of land that connected the UK to the rest of Europe a million years ago. They would have disappeared around 800,000 years ago because of a much colder climate setting in not long after the footprints were made.

It was not until 500,000 years ago that a species called Homo heidelbergensis lived in the UK. It is thought that these people evolved into early Neanderthals some 400,000 years ago. The Neanderthals then lived in Britain intermittently until about 40,000 years ago - a time that coincided with the arrival of our species, Homo sapiens.

There are no fossils of antecessor in Happisburgh, but the circumstantial evidence of their presence is getting stronger by the day.

In 2010, the same research team discovered the stone tools used by such people. And the discovery of the footprints now all but confirms that humans were in Britain nearly a million years ago, according to Prof Chris Stringer of the Natural History Museum, who is also involved in the research at Happisburgh.

"This discovery gives us even more concrete evidence that there were people there," he told BBC News. "We can now start to look at a group of people and their everyday activities. And if we keep looking, we will find even more evidence of them, hopefully even human fossils. That would be my dream".

据英国广播公司2月7日报道，科学家在英格兰东部黑斯堡海岸上发现80多万年前的人类脚印遗迹，这是非洲之外最古老的人类脚印遗迹，直接证明欧洲北部早期人类的存在。

来自英国国家博物馆的迪克•阿什顿博士和同事们在2013年5月发现这些脚印。当时海水冲刷，带走海滩上的沙子，脚印遗迹暴露在外。阿什顿当时想：“这怎么可能是真的呢？如果真的是这样，它们就是欧洲以外最古老的脚印了，真让人难以置信。”

类似发现极其罕见，全世界最古老的3处人类脚印遗迹都在非洲。论年代，本次发现排名第4。

阿什顿说：“刚开始我们不知道这是什么，但很快就发现这些坑洞很像人类脚印。”不久之后，。研究人员赶在脚印被海浪冲刷殆尽之前拍下了视频，并且将在伦敦自然历史博物馆展播。视频中，研究人员冒着雨、争分夺秒地从脚印中舀出雨水，方便拍摄。

发现脚印后的2周里，研究人员对脚印进行了3D扫描。伊莎贝尔•德格罗特博士仔细分析后认定，它们的确是人类脚印，还说能还原包括脚跟、足弓和脚趾在内的部分脚部模型。这些脚印来自一名成年男子、几个孩子、以及另外5个人。男子身高约为1.75米，最矮的儿童有0.91米左右。其中最大的一只脚今天能穿42号鞋。德格罗特认为这可能是一家人在赶路。

脚印主人的身份目前还是个谜。有人猜测他们可能是早前住在欧洲南部的先驱人（Homo antecessor），大约100万年前迁徙而来，但是无法忍受寒冷的气候，在80万年前消亡。科学家还没有在黑斯堡地区发现先驱人的化石，但曾在2010年发现他们的石制工具。自然历史博物馆的克里斯•斯特林格教授对未来充满希望，他说：“本次发现带来更多切实证据证明，这里曾经有过人类……如果我们继续寻找，就能找到更多证据，甚至人类化石也有可能。”