Climate determined human occupation of Britain
Until recently, it was thought that ancient humans arrived in Britain 500,000 years ago. But new discoveries paint a different picture. Stone tools have been dated to 700,000 years. Other specimens appeared 900,000 years ago. It seems Britain was joined to Europe, then cut off, then joined up again, as sea levels changed. At times, the whole of Britain was covered with vast ice sheets making human occupation impossible. It is now thought that Britain was colonised with ancient humans from Europe many times, with humans dying out nine times over history as the deep freeze moved further south. Further recent revelations show humans cannibalised each other as recently as 15,000 years ago.
Robyn Williams: Are you an ancient human? I am, having grown up to some extent in Britain, it now astounds me that anybody actually survived for any length of time as the ice sheet covered everything, and as Britain was at one stage merely a peninsular of France. Meet once more Dr Chris Stringer from the Natural History Museum in London.
Chris Stringer: Well, yes, the British island, it was often a peninsular of Europe, so there was a land bridge much the time in the past, in the distant past, joining us to the rest of Europe. And we used to think that humans got to Britain first of all about 500,000 years ago, which is a respectable antiquity, but obviously nothing compared with the south of Europe and compared with Africa.
But I've been involved in the project now for the last 13 years called the Ancient Human Occupation of Britain Project, and this has been looking at the evidence and we've been, if you like, digging deeper into these British sites where no one really expected to find evidence of early humans but we have found them, beyond 500,000 years.
So at a site in Suffolk called Pakefield we found stone tools that date from around 700,000 years ago when humans were able to get across this land bridge and Britain was actually quite warm, it had a Mediterranean-like climate. And then remarkably in Norfolk we managed to take the story even further back at a site called Happisburgh where from about 900,000 years ago we have stone tools that suggest people were there then. We don't unfortunately have their fossil remains, we have only the artefacts, they made very simple artefacts. We suspect this could be the same species as we have in Spain at that time, a species that has been called Homo antecessor, pioneer man.
Robyn Williams: The picture you're getting, as we discussed before, is that Britain got cut off…was it once or twice?
Chris Stringer: Well, Britain in fact got cut off many times really. In terms of habitable environment it was cut off at least every 100,000 years by extreme cold. So during the last million years we've had increasingly fierce cold stages where Britain was either covered with ice sheets over most of the land mass, or was essentially uninhabitable because the environment was like, say, northern Scandinavia at the present day. So in those periods, early humans just weren't able to survive, and we actually lose any trace of people. So all these early colonisations, including the one at Boxgrove, the one at Pakefield, the one at Happisburgh, we think those populations were wiped out. When the climate deteriorated they actually died out. And so Britain had to be repopulated all over again, this has happened at least nine times. There were unsuccessful colonisation events, and we now in the last 12,000 years are the successful colonisers, at least for now.
Robyn Williams: One picture you've got which I found absolutely incredible, is the river Thames didn't meander out, you know, going through London, which of course didn't exist then, but wandering out straight west, but went north and joined the Rhine. How?
Chris Stringer: Yes, that's something that with these changes in geography, with these changes in ice caps and the land being eroded by the advancing ice, things like river systems were greatly affected. So in the distant past the Thames was indeed much further north, and it ran out into the North Sea at the site of Happisburgh where we've been digging. So this massive river there is actually the river Thames. And what happened was that about 450,000 years ago the biggest ice sheet that came down across Britain actually wiped out a lot of river systems that were further north completely, and the Thames got pushed south by this huge ice sheet and it gradually came to occupy the present river channel that is much further south and runs through London.
So when we go back to 900,000 years ago, the Thames is up in Norfolk, and then progressively we see it pushed further and further south by each of these changes in the geography. And then after 450,000 years ago we start to see evidence of the formation of the English Channel. And when the English Channel formed, okay, potentially Britain could become an island if the sea level was high enough, as it is at the present day, as it was 125,000 years ago, but also during the times of low sea level you had a completely new area for the rivers to flow through. And actually the river Thames and the river Rhine joined up where the North Sea is today and then they flowed south westwards through this river channel out into the Atlantic.
Robyn Williams: And the Channel Islands way back were part of France. What have you found there?
Chris Stringer: Yes, our team and collaborators have been working at a site called La Cotte de St Brelade on the island of Jersey, and Jersey of course is geographically very close to France. Most of the time, particularly at times of low sea level, it was physically joined to the rest of France. We know that early Neanderthals were there 150,000 or 200,000 years ago, some Neanderthal teeth that are maybe 50,000 years old had been excavated from that site. And so we've been revisiting, with collaborators, this famous sight of La Cotte de St Brelade, and this has got really deep deposits covering probably 200,000 years of early human occupation. This is giving us a view, if you like, of the other side of the Channel.
Robyn Williams: Before we go out and have a look at a tiny number of specimens from…is it the Thames?
Chris Stringer: Yes, we're going to look at some material from the Thames, which is a fantastic location for fossil finds.
Robyn Williams: Well, let me just confirm that all of this we've been talking about is going to be on display at the Natural History Museum from February next year, 2014, for people to look at.
Chris Stringer: That's right, yes, so we're going to have an exhibition here for six months, and it will bring together for the first time all the human remains from these ancient times found in Britain. So we will have the material from Boxgrove, we will have early Neanderthal teeth from a cave in Wales called Pontnewydd, we will have early modern human fossils including the skeleton from Haviland in Wales, and we will have the material from Gough's Cave in Cheddar which shows that modern humans were probably cannibalising each other about 15,000 years ago. So a bit of a gruesome story there. But it will all be there in this exhibition which is called 'Britain: One Million Years of the Human Story'.
Robyn Williams: Okay, let's struggle out to look at some of the specimens. And while we do, leaving your wonderfully crowded office, I have one question about your last remark, which is how can you tell that someone was cannibalised?
Chris Stringer: Well, yes, first of all these particular remains were disposed of along with animal remains that were butchered for food, and these remains were thrown away with them, so that's the first thing. And also these bones are actually covered in cut marks. The long bones were broken open to extract the marrow, and some of the skulls were actually sculpted around their rims, and it looks like they turned them into drinking cups or drinking bowls for some kind of ritual. So it's a bit of a gruesome story going on here nearly 15,000 years ago.
Robyn Williams: You're taking me down one of these lovely corridors in the Natural History Museum which is absolutely full of the most incredible treasures.
Chris Stringer: Let's have a look here first of all. This is going to give you just a flavour of the kind of material that comes from the river Thames.
Robyn Williams: Ah, shelf after shelf of great big bones, they're huge.
Chris Stringer: And for anyone who knows London, we've got familiar locations; Isleworth, Uxbridge. Let's carry on down here. Brentford. So here's a rhinoceros skull, a woolly rhino from Brentford. Here's a mammoth from Salisbury Square. Here's a woolly rhino from Ealing. So, as you can see, beautifully preserved material, whole jawbones of a mammoth there and you can see just the size of these teeth. That's a single molar tooth of that mammoth…
Robyn Williams: With all those ridges.
Chris Stringer: Yes, that's right.
Robyn Williams: Just like elephants have got ridged teeth to chew.
Chris Stringer: That's right, yes. So this is just a sample of what the river Thames has produced, and of course when you sink any foundations for buildings in the London area into the Thames terraces, you may well find remains like this, and some of the most interesting came from Trafalgar Square, which we'll have a look at…
Robyn Williams: I don't believe it. Of course the incredible thing is you keep finding bodies under car parks and stations. One thing we are going to follow up later is rather more modern, Flinders, of Australian fame, is actually under the platforms at Euston Station, there's going to be a statue of…now I'm looking at all these creatures.
Chris Stringer: And so here we've got a postcard and this is a sort of mock-up, and in the background you can see the National Gallery in Trafalgar Square, and in the foreground you've got the remains of animals that have turned up from foundations of buildings on the south side of Trafalgar Square. And you would guess you were in Africa just looking at that picture probably because you’ve got lions, you've got rhinos, you've got elephants, you've got hippopotamuses. And they were swimming in the river Thames 125,000 years ago. So incredibly this was what Trafalgar Square was like at that time, and these animals were living here with no human hunters.
So the Neanderthals who were over in continental Europe, at this time the Channel had formed, they didn't have the boats, they couldn't get across. These animals were able to either get across the land bridge before it was swapped, or they could swim across in the case of the hippos and the elephants. And all the details in this reconstruction are based on material found at Trafalgar Square, even the insect and the plant remains. So Britain was actually even slightly warmer than it is at the present day. The summers were probably at least one degree warmer than they are today. And these animals were okay, they were getting along fine without a single human hunter. So we found no cut marks in any of these bones, there are no stone tools associated with any of these remains. This was Britain without people 125,000 years ago.
Robyn Williams: Dr Chris Stringer at the Natural History Museum in London, where the ancient human exhibition opens in February.
- Chris Stringer
- Research Leader in Human Origins
Natural History Museum
- Homo Britannicus: The Incredible Story of Human Life in Britain
- Chris Stringer
- Penguin UK
- Robyn Williams
- David Fisher