Professor Danielle Schreve
Appearances
The Ancients
End of Ice Age Britain
So permafrost conditions, very, very cold indeed. Britain is connected to continental Europe at that time because sea level was much lower. That's because water is drawn off during the buildup of the ice sheets on land. There's evaporation of the water from the oceans, and sea levels fall by about 120 meters globally. That's more than enough to reconnect Britain to the continent.
The Ancients
End of Ice Age Britain
So there is a land bridge in the southern part of the North Sea Basin. So it would be possible for species that were able to tolerate those conditions to move in and out, but it would have been a pretty inhospitable place.
The Ancients
End of Ice Age Britain
There's a surprising number of species, I would say. I mean, biodiversity is, of course, much lower than you would find in many warmer climate periods. But nevertheless, we still get some smaller species around. So we find, for example, evidence of mountain hare. We also have remains of cold adapted species such as woolly mammoth. We have also reindeer around, for example.
The Ancients
End of Ice Age Britain
But some of the most interesting remains that we've got are things like muskox, which are obviously obligate cold species. They live today up in the high Arctic. And yet they were living around, for example, Northamptonshire. We've got a series of muskox remains that are dated to about 20,000 years ago.
The Ancients
End of Ice Age Britain
So that is a really, really clear indication of just how different conditions were on the ground at that time. Wow.
The Ancients
End of Ice Age Britain
There's no unequivocal evidence of humans being present. So it's a tricky one because I think when you have certainly a period of very cold climate conditions, often it's hard for material to get preserved because just the cold and the action of ice sheets, it's not conducive to the preservation of fossil material.
The Ancients
End of Ice Age Britain
Now, certainly across Northern Europe, there were other areas that were believed to be abandoned by modern humans at the time, but of which have been demonstrated subsequently to have some limited evidence. So, it's possible that humans were making forays into Britain at that time, perhaps during the slightly warmer parts of the summer months. But we really don't have any good evidence.
The Ancients
End of Ice Age Britain
We don't have any artefacts. And there is a putative human humorous from a site in South Wales that may date to this period. But certainly if people were around, they are in low numbers and they are not long-term residents. Music
The Ancients
End of Ice Age Britain
It has to be lower than the ice sheets. I think you might have had some species that perhaps could tolerate being out on the open ice, so much further to the north, although we don't have evidence preserved. You might have got things like polar bear, for example, at the very highest latitudes. But really, for the herbivores, of course, they need something to eat. They need vegetation.
The Ancients
End of Ice Age Britain
So they cannot survive out on an open ice sheet. They have to have vegetation. And in the case of something like a reindeer, that can be fairly short grasses and lichen that they might be feeding on. But it's not like having a herbivore. There's not a herbivore bonanza up on the ice sheet. You might have had polar bears that are predating on seals, for example.
The Ancients
End of Ice Age Britain
in the way that they would do in high latitudes today. But really, everything is going to be south of that ice sheet limit.
The Ancients
End of Ice Age Britain
So at the end of the last glacial maximum, we enter a period of abrupt warming. And this is referred to as the late glacial interstadial. It's about 14,500 years ago. And it marks the sort of first evidence towards a significant warming. albeit later interrupted, but a warming and really sort of, you know, the end of the last ice age. So that warming event is very abrupt.
The Ancients
End of Ice Age Britain
Really, you're looking at rapid warming conditions in Northwest Europe. So the ice sheets begin to retreat. And really by, you know, sort of about 16,000 years ago, they are much, you know, they're much reduced up to the northern part of Britain.
The Ancients
End of Ice Age Britain
We do because we can measure these things, for example, by going to the ice sheets in Greenland. Oh, wow. Yes. So you can extract ice cores from Greenland and they have annual records in them where they've got things like greenhouse gases trapped. So we're able to measure this and document this really, really accurately. closely. We can date those bands in the ice.
The Ancients
End of Ice Age Britain
And so we do have a very good idea about just how quickly some of these transitions took place.
The Ancients
End of Ice Age Britain
It's a great sort of archive, if you like. It's a great benchmark for understanding how climate change in this part of the Northern Hemisphere happened. And because Britain is, you know, really quite close in that part of the North Atlantic, we can actually see the major transitions as we come out of the last glacial maximum.
The Ancients
End of Ice Age Britain
the rapid warming into the late glacial interstitial, and then some of the subsequent oscillations, the climatic fluctuations that we see, we can actually see that evidenced on land in Britain.
The Ancients
End of Ice Age Britain
So at that time, you would see a retreat of some of the species that had been adapted to very cold conditions. So things like mammoths begin to contract their range back to Siberia. During the late glacial interstitial in Britain, you do get other species that are cold adapted that still hang on. So things like reindeer are still regularly present.
The Ancients
End of Ice Age Britain
But because of the warming event that we see, we get other types of herbivores in particular coming in. At first, things like horse and then subsequently red deer. We get a real mix of species at that time though. For example, in the cave sites that we're working in in Somerset, we get both species that are today indicative of cold climate conditions. For example, things like collared lemmings.
The Ancients
End of Ice Age Britain
Those are mixed in with other small mammal species that require more temperate but also some kind of vegetation cover as well. These might be things like wood mice, for example, or common shrews.
The Ancients
End of Ice Age Britain
These are small mammals that we think are probably able to eke out an existence in some of these very deep limestone gorges, particularly where there are more shrubby habitats or even trees that are growing there.
The Ancients
End of Ice Age Britain
there would have been sufficient shelter to support both the ones that needed more temperate conditions, but also up on the plateau, you've still got pretty exposed conditions and you would have been able to support things like reindeer up there as well.
The Ancients
End of Ice Age Britain
Yes, and I think certainly back in the past, we used to wonder whether these were sort of jumbles in the fossil record, that there wasn't good resolution in these sites, that we didn't have the precision to say level by level exactly what was going on. But now, for example, with the types of sites that we're working on, we have got really good resolution.
The Ancients
End of Ice Age Britain
So actually, we can see that within just a few centimetres of sediment, we can extract these animals that have rather different habitat preferences together. It really has an important lesson, I think, for how we understand fauna and responses to climate change at the present day, because it shows us how quickly animals can respond to these events.
The Ancients
End of Ice Age Britain
And obviously, one of the challenges that they have today is the fact that we have changed the landscape. We've removed connectivity of habitats. But in the past, even very small animals could expand or contract their range according to changing environments, changing climates. They could do that really, really rapidly.
The Ancients
End of Ice Age Britain
So animals such as, you know, many of these animals would be relatively more tolerant as mammals because mammals are warm-blooded and they would have had certain adaptations as well. They're certainly more tolerant than things like reptiles or amphibians that are obviously completely dependent on external temperatures.
The Ancients
End of Ice Age Britain
So mammals can often, because they can maintain their body against a temperature gradient, they can often survive in more marginal areas outside their sort of core range. But yes, the story there is very much one of move, adapt or die out. So we've already seen some species such as woolly rhino disappear from Britain about 35,000 years ago, but they live for another 20,000 years up in Siberia.
The Ancients
End of Ice Age Britain
And so when we look at, for example, the extinction of species, we need to understand that it's different triggers in different parts of their range at different times. So species are not necessarily responding as communities here, but very much as individuals. And some of them, you know, the climate change is too quick for them to adapt, really.
The Ancients
End of Ice Age Britain
So actually, although some of them may be able to switch to different food sources, often the way that they would sort of get out of difficulty is to change their range. So they would migrate to areas that were more favourable.
The Ancients
End of Ice Age Britain
Humans are around during the late glacial interstitial and they come back just before the warming event. So they're really poised and ready to come back into Britain. And they seem to occupy areas of the southwest first and then move further north into the Midlands. And we're able to establish this because of very precise radiocarbon dating.
The Ancients
End of Ice Age Britain
We know that when they come in at about 14,500 years ago or just before – They are primarily hunting horse, but also going after things like red deer as well. And then later on, they move to doing things like trapping mountain hare and exploiting those. So that's really interesting that there is a switch to smaller game.
The Ancients
End of Ice Age Britain
And that's consistent with the disappearance of things like the megafauna, that people are having to adapt their diets as their own environment changes and they're having to switch to different food sources.
The Ancients
End of Ice Age Britain
Indeed. So, Gough's Cave was a really spectacular site and probably supported a decent group of individuals for perhaps a couple of hundred years. And even though this site was dug, primarily excavated a long time ago during the Victorian period, There have been more recent excavations of remnants of the sediments that were preserved below overhangs on the side of the cave walls.
The Ancients
End of Ice Age Britain
Those were carried out by colleagues from the Natural History Museum in the 1980s. One of the most astonishing things about Gough's cave is the abundance of actual human remains. So in fact, human remains generally, whether it's modern humans, whether it's Neanderthals or their forebears, are so incredibly rare in Britain.
The Ancients
End of Ice Age Britain
And yet they make up approximately a quarter of all the material that came out of Gough's cave. And in fact, there are sort of anecdotes about, I think, 12 tea chests full of bones being removed from the cave and essentially destroyed because they were viewed as duplicates. And when you think about the amount of material that must have been lost,
The Ancients
End of Ice Age Britain
So the Goff's Cave remains are very special, partly because there's good evidence of humans, but also because of the superb preservation of the material. And we can see the remains of animals, whether it's, for example, butchered horses. We see cut marks on horse teeth, on horse bones. We see exploitation of red deer. There's remains of carnivores, such as lynx.
The Ancients
End of Ice Age Britain
that are present in the site and almost certainly exploited in the case of the lynx for its lovely pelt for the fur. We see exploitation of things like mountain hare and the modification of hare bones into little tools such as piercing, sort of all type tools. Really just a very sort of complete picture of what humans are doing.
The Ancients
End of Ice Age Britain
And of course, one of the most notorious things there is that there is also evidence of breakage of bone for marrow extraction and butchery of the human remains themselves. So those humans are being treated in exactly the same way as any other butchered animal bone at the site.
The Ancients
End of Ice Age Britain
It's Somerset, right in the Mendips. So it's partway up Cheddar Gorge. So a really well-known area that people can go and explore. And you can walk into the cave today. And it's a visitor attraction. And the Paleolithic or old Stone Age deposits are very close to the entrance of the cave, just sort of tucked away on the left-hand side as you come in.
The Ancients
End of Ice Age Britain
Yes, I think just as we seem to be climbing out of the last ice age, we have a sudden reversal of conditions and a huge climatic deterioration. This is a period known as the Younger Dryas. It starts about 12,900 years ago and it finishes about 11,700 years ago. Pretty precise dates as well for Paleolithic times too. Pretty precise dates.
The Ancients
End of Ice Age Britain
And again, we can get that chronology from the Greenland ice core, but also, of course, with the benefit of radiocarbon dating as well. So, we know quite a lot about this time period in terms of the effects on land of this sudden deterioration in climate. And Broadly speaking, that's caused by a mixture of factors.
The Ancients
End of Ice Age Britain
So there is some evidence, for example, from Germany, from the Eifel region, that there is a period of intense volcanism, so volcanic activity that precipitates a cooling in climate. But also there are other things going on at this time.
The Ancients
End of Ice Age Britain
So particularly in North America, you've got the decay of the big ice sheets, the Laurentide ice sheet, and pulses of very cold meltwater that are entering the North Atlantic. What they do is to disrupt the ocean circulation, and Britain is plunged back into the freezer once more.
The Ancients
End of Ice Age Britain
Again, this would have been an abrupt reversal of fortune for a lot of the more temperate adapted species. Certainly, in the caves that we've been digging in Ebba Gorge, we can find, for example, evidence of reindeer. There's also evidence of arctic fox in there. There's several individuals, including a complete specimen that was curled up in a little niche at the back of the site.
The Ancients
End of Ice Age Britain
So beautifully preserved. There's lots of crunched up bone in there as well. So you can imagine the arctic foxes running in and out of the cave. They are predating small mammals. So we get a variety of small mammal species that are present, but also things like birds as well. So species that we would find in the northern part of Britain today. So things like ptarmigan,
The Ancients
End of Ice Age Britain
Again, those small species are on the move very rapidly. Within the cave site, we have remains of three species of lemming that today are not sympatric, by which I mean they don't live together today. So we have remains of Norway lemming, which come from Scandinavia. We have remains of collared lemming that today have a sort of circumpolar distribution in the Northern Hemisphere.
The Ancients
End of Ice Age Britain
And we have only the second record from Britain of a Siberian steppe lemming. And all those three species congregate in the southwest of Britain during the Younger Dryas. So again, these things were expanding their range very rapidly.
The Ancients
End of Ice Age Britain
Yes, it certainly is for those particular species. There is another species called a wood lemming, though it inhabits more boreal forests today in Scandinavia.
The Ancients
End of Ice Age Britain
Traditionally, very difficult to separate from things like the Norway lemming, but through a mixture of ancient DNA and also very novel types of shape analysis on the teeth, we've been able to separate out the wood lemming species from the Norway lemming species.
The Ancients
End of Ice Age Britain
And because they both like different types of environment, that's been really important for us in terms of understanding the local vegetation. So if we have something like a Norway lemming, these are typical tundra species. They can tolerate sort of fairly boggy types of environment. They would feed on grasses and sedges.
The Ancients
End of Ice Age Britain
And we know that obviously they can tolerate snow cover and they are a great indicator of local conditions on the ground.
The Ancients
End of Ice Age Britain
perhaps not quite as cold, but still a shock to the system. So, you're looking at really a sort of, I guess, a decrease of perhaps four or five degrees centigrade in terms of air temperatures, certainly for the Younger Dryas across Europe. It's not the same globally.
The Ancients
End of Ice Age Britain
So, the Younger Dryas is manifested differently in different parts of the world, but certainly that's what we would expect for Northwest Europe.
The Ancients
End of Ice Age Britain
It is indeed. So we often use local stage names, which are particularly appropriate for Britain. So if you were to say the Loch Lomond Stadium, people would understand exactly what that was. And that also conjures up a very specific set of circumstances. So the presence of ice sheets up in Scotland, the kinds of cold climate animals that we've been describing just now,
The Ancients
End of Ice Age Britain
Whereas, obviously, if the Younger Dryas is manifested differently in different parts of the world, then they would also have their own local stage names as well.
The Ancients
End of Ice Age Britain
So, saiga antelope are fantastic animals and they are a small bovid, a small antelope. They live today in really the sort of heartlands of dry central and eastern Asia, so particularly populations in Mongolia and Kazakhstan. Until recently, they have been critically endangered, but thank goodness their numbers are now on the rise again.
The Ancients
End of Ice Age Britain
They are very well adapted to living in arid and pretty dusty environments. If you happen to look them up and you see photos of them, you'll see that they have this fantastic nozzle-like nose. They can use it to filter that dry, dusty air, cold air before it gets into the lungs.
The Ancients
End of Ice Age Britain
And although they are essentially Central Asian animals and always have been, in response to this sort of cold and arid pulse that we find in the Younger Dryas, they expand their range at the time. We find them over in Alaska and to the west, we find them over in Somerset. So there are radiocarbon-dated remains from Gough's cave and also from some other cave sites in Cheddar Gorge as well.
The Ancients
End of Ice Age Britain
Absolutely. I think some of the changes that were witnessed, whether it's to do with the landscape, the environment, the fauna, they're just some of the most remarkable changes that Britain has ever witnessed.
The Ancients
End of Ice Age Britain
So a fantastic but rare addition to the fauna in Britain at this time.
The Ancients
End of Ice Age Britain
No, again, we just don't have the sites. Certainly at the sites that we've been working on in Ebba Gorge, we don't have evidence of artefacts, we don't have evidence of cut-marked remains, and we certainly don't have evidence of people themselves.
The Ancients
End of Ice Age Britain
So again, it's perfectly possible that people were making occasional forays into Britain, but we think that Britain was largely abandoned during this period.
The Ancients
End of Ice Age Britain
So we're back on that warming trajectory. And again, there is rapid warming. And the early part of the current interglacial, the Holocene, is even warmer than at the present day. And then we sort of settle down to a period of relative climatic stability.
The Ancients
End of Ice Age Britain
But yes, the real end of the ice age, you start to see really up in Scotland, you start to see the last of those glaciers, those ice sheets disappear. retracting and leaving behind what we call dead ice environments. So for example, lakes, you would have had the ice melting and creating a lot of lakes in areas of sort of deeper topography.
The Ancients
End of Ice Age Britain
You would have had a window of opportunity for animals and people to come back into Britain before sea level rises and cuts us off completely. So, remember that land bridge that had existed for pretty much all of the last ice age? That is becoming smaller and smaller.
The Ancients
End of Ice Age Britain
As that ice across the northern hemisphere melts and the water is returned to the ocean, that land bridge becomes more and more compressed and harder and harder to access. So, people and animals would have come back into Britain very rapidly.
The Ancients
End of Ice Age Britain
We see things like reindeer hanging on for a little while into the early part of the current warm stage, but eventually it becomes too warm and too wooded for them to survive and they go locally extinct. Instead, we see a whole suite of fauna that we would regard as native species coming into Britain in the early part of the warm stage.
The Ancients
End of Ice Age Britain
These are things like aurochs, the ancestor of our domestic cattle. We had things like elk or moose, as it's known in North America. Red deer would have been abundant, roe deer, wild boar. These are the major sort of herbivore food stock, really, for the last hunter-gatherers that we find in Britain. And those are the Mesolithic peoples.
The Ancients
End of Ice Age Britain
Definitely, thousands of years. So I think probably a sensible starting point is probably the period that we would call the last glacial maximum. So from about 26,000 years ago until really the early parts of the current warm stage or interglacial that we're in now.
The Ancients
End of Ice Age Britain
Yes, so some of those species have gone right the way through to the present day. So red deer, roe deer would be a case in point. Others, such as the last remaining carnivores, whether they happen to be brown bears, lynx or wolves, we hunted to extinction really sort of from the Middle Ages onwards.
The Ancients
End of Ice Age Britain
Other things like elk disappear quite early on in the Holocene, again, probably hunted to extinction. And some of those smaller species as well. So the Arctic foxes have gone, but instead we have red fox. We have things like wildcat as well. And they're all distributed really all over Britain.
The Ancients
End of Ice Age Britain
So things like wildcat, which today survive only up in the Scottish Highlands, their natural habitat, which we can see from the fossil evidence, is actually deciduous woodland. And so the fossil record is
The Ancients
End of Ice Age Britain
can play a really important role here in helping to address modern conservation issues today by giving more detailed baseline information about where species should be distributed or where they should be reintroduced today. So one of the youngest specimens that we have from the Mendip Hills, from the excavations, is a beautiful complete skeleton of a wildcat.
The Ancients
End of Ice Age Britain
and it was found in association with other evidence that indicates warm and wooded conditions. So this was really optimal habitat for them.
The Ancients
End of Ice Age Britain
Technically by 11,700. That's when we would say, yep. I mean, it depends whether you count in radiocarbon years before the present, or, you know, some people look at it from a sort of, you know, BC or before the common era. So round about that, you know, 11,700 years before the present day, that would be when we consider the, you And we've got those warm and wooded conditions.
The Ancients
End of Ice Age Britain
And then obviously, you know, some spectacular transitions further in the human journey, really. And the move from hunter-gatherers to settled peoples and agriculture, all of these things then kick off.
The Ancients
End of Ice Age Britain
It's a really nice question to end on because this is one of the things that I think is so important and it's something that we're really trying to push and to work with modern ecologists. And so I've got a lot of great work that's starting with, for example, Natural England and other colleagues, particularly around some of these sort of joined up super national nature reserves that
The Ancients
End of Ice Age Britain
where there are some really exciting developments that are in play, involving perhaps reintroduction of large herbivores to modify the landscape. The disappearance of many species is only just starting to be understood in terms of their legacy. The important things that elk and bison, for example, that they had in terms of
The Ancients
End of Ice Age Britain
opening up the vegetation, in terms of fertilising the land with their dung, in terms of transporting seeds around, all sorts of things that we have lost in the way of ecological benefits.
The Ancients
End of Ice Age Britain
We are understanding very well now how animals such as beavers, ecosystem engineers, the role that they can play in terms of helping to control completely cost-free flooding episodes by trapping water upstream and away from areas of human settlement. But there's a lot more to be done.
The Ancients
End of Ice Age Britain
And really, the fossil record can give a really important insight, working hand in hand with ecologists in terms of understanding the range, the habitats, coexistence of different species and different behaviours in the past. We can provide a more nuanced insight.
The Ancients
End of Ice Age Britain
insight into for example things like species distribution models where we think about where animals could and should be distributed especially in view of climate change in the future and the fossil record can help us make better informed decisions in terms of the conservation of those species so a really important role to play and some really exciting work to be done in the future.
The Ancients
End of Ice Age Britain
We do. So I think it's important to make a difference between archaeological material, which would be that related exclusively to humans, so things like human artefacts, whether that's stone tools or other types of evidence, and the sort of paleobiological evidence that we might have. So things like fossils of animal bones, plant remains, shells, that kind of thing.
The Ancients
End of Ice Age Britain
So, we have lots of different types of evidence that are available to us, and sometimes that comes in the form of the sediments themselves, because the deposits of sands and gravels and all sorts of things that we might actually dig into, we can understand a story of how climate changed from those.
The Ancients
End of Ice Age Britain
We can also look at the remains of animals and plants, and they tell us very clearly how things change in response to climate change, often very rapid and abrupt climate change. There's also different types of evidence out there as well. For example, things like sea level rise. We know that at times Britain was connected to the continental mainland.
The Ancients
End of Ice Age Britain
And then as we come towards the end of the last ice age, the sea level rises and Britain becomes cut off. So actually, there's a whole host of different types of evidence out there.
The Ancients
End of Ice Age Britain
Definitely. So one of the things we try to do is to reconstruct that landscape. So to understand, for example, the changing coastline of Britain. Britain is in quite an extraordinary position, really, at the edge of the North Atlantic. So it's very sensitive to climate change. And we can get at that evidence for change through doing things like coring,
The Ancients
End of Ice Age Britain
into deposits that might be, for example, buried below the sea now, but also on land as well, and actually looking at those cores of sediment through time and extracting as much information from them as possible.
The Ancients
End of Ice Age Britain
Yes. So, paleoecology or paleoecology really deals with the ecology of the past. So, the paleo bit just means the old part. So, in the same way that an ecologist today would look at the habitats, the behaviour, all aspects of the ecology of the animals that they might study today, this is what I'm trying to do in the past.
The Ancients
End of Ice Age Britain
And sometimes it's easy or relatively easy because the animals that I study are still around today or very close relatives. In other cases where you've got animals that are extinct today, we have to draw on different lines of evidence in order to try and reconstruct something of their life ways.
The Ancients
End of Ice Age Britain
So fauna is animal life. And by that, anything could come into fauna, whether it's, for example, vertebrates. So that might be fish, reptiles, amphibians, birds, mammals. But it could also include all sorts of invertebrates as well. So particularly things like beetles, snail shells, that kind of thing as well. So it covers a very broad range of different types of material.
The Ancients
End of Ice Age Britain
Definitely. And one of the things that I am interested in is studying the fauna as a whole. So not just focusing in on sort of the biggest, most impressive species, although obviously things like the megafauna are really interesting and charismatic animals, but actually things like small mammals as well. They can tell you a phenomenal amount about the local environment, about climate.
The Ancients
End of Ice Age Britain
Small things like beetles are really good for reconstructing climate events in the past and telling you about local vegetation. And some sites preserve some types of evidence better than others. So we need to go after all of them in order to try and reconstruct the best, most holistic picture that we can.
The Ancients
End of Ice Age Britain
They can indeed. So I guess it's a moot point whether you want to include humans as part of the fauna. I think for much of the past, the Paleolithic or Old Stone Age, humans are doing something interesting in the landscape. They are certainly doing unusual things like making stone tools, but they're very much part of a wider fauna.
The Ancients
End of Ice Age Britain
They're responding to the same kind of climatic and environmental trends that other species are. Luckily, they do leave behind useful things like stone tools, so we are able to derive an enormous amount of information from that in terms of their behaviour.
The Ancients
End of Ice Age Britain
Remains of the actual early humans themselves are very rare in the UK, but we do have other types of evidence, for example, things like cut marked bones and broken bones, which tell us about butchery and hunting practices as well.
The Ancients
End of Ice Age Britain
So cave sites are often really good places to target for this type of information. They can be very rich resources of information. Often, of course, we have caves that form in limestone areas across the UK. So things like the southwest of England, the Peak District, South Wales, for example, North Wales. These are all really good places for finding material in caves.
The Ancients
End of Ice Age Britain
And you can often get a buildup of quite long sequences through time as well. And that's because caves act as large repositories or archives for material coming in. And sometimes it might be washed in by a river or a mudflow. But a lot of times you get cave sediments building up over time and containing the remains of animals that were either living in the cave or
The Ancients
End of Ice Age Britain
so things like carnivores, for example, or which were brought in as remains of prey. And that can build up over long periods. So caves are great generally for preserving animal remains in the form of bones or teeth. They're also very good for preserving mollusk and shell.
The Ancients
End of Ice Age Britain
But they are not so good at preserving things like pollen or what we call plant macrofossils, so bits of plant, whether it's bits of leaf or twig or seed, for example. And that's just because limestone tends – I mean, it's a very calcareous environment.
The Ancients
End of Ice Age Britain
So it's good at preserving things like bones, and it's not good at preserving things like pollen, which needs a more acidic type of depositional environment.
The Ancients
End of Ice Age Britain
Yes, it's very alkaline. So that's good for the preservation of bones and teeth.
The Ancients
End of Ice Age Britain
So we get different types of evidence from these caves, but they can often contain really detailed sequences that allow us to examine how animals and indeed people on occasion, if we have evidence for archaeology in those caves, we can examine how the fauna, how people have been responding to climate and environmental change.
The Ancients
End of Ice Age Britain
So this is work we've been doing for a number of years now, about 15 years. And it's based in a previously unexplored cave site in the Mendip Hills in Somerset. So it was a wonderful opportunity to explore a site that had not had any previous excavation in it. So already that's quite rare because many cave sites have been discovered. They were discovered by Victorian antiquarians.
The Ancients
End of Ice Age Britain
They certainly did. They were very keen on finding things like specimens for their cabinet of curiosities. They would go out. In some cases, there were rather systematic excavations done. In other cases, people were literally going along and looking for souvenirs.
The Ancients
End of Ice Age Britain
All of this happened at a very exciting time, and in fact, Britain and places like the Mendip Hills played a crucial part in that move away from the teachings of the church and understanding about evolution, the discovery of the bones of extinct animals, and then later in association with human tools as well. This was really the first insights into the antiquity of humans.
The Ancients
End of Ice Age Britain
So the Mendip Hills have always been a great place to work. And the research that we've been doing in this particular cave site has generated some fantastic information. We have a sequence that goes back over 50,000 years now. And it's one of the most important sites, certainly in Britain and in Northwest Europe.
The Ancients
End of Ice Age Britain
We're talking about hundreds of mammal bones. Now they're not all complete. It's important to say that because at some levels within the cave, we have things like spotted hyenas that have been denning there and they're crunching up the bones. So we collect all of the fragments because even the very broken bits tell us something about the origins of what we call an assemblage.
The Ancients
End of Ice Age Britain
So that collection of bits of bone and they tell us what those animals were up to. But at this particular cave site in Ebba Gorge, we have, for example, in some of the upper layers, we have got hundreds of thousands of bits of small mammal. So these might be things like bats, mice, voles, shrews, lemmings.
The Ancients
End of Ice Age Britain
They've been brought in by birds of prey that have been hunting over the landscape, that have swallowed this material down. They come back to the cave to roost, and then they regurgitate the undigested bits as pellets. Eventually, thousands of years later, those have started to turn into fossils, and that's when we can come along and collect them.
The Ancients
End of Ice Age Britain
The Last Glacial Maximum, Britain, was a pretty chilly place, so subject to really savage cold. So as the name implies, the Last Glacial Maximum witnesses the coldest point of the last ice age, which began about 100,000 years ago. Around about 26,000-25,000 years ago, you get the expansion of ice sheets in Britain. They cover all of Scotland. They cover almost all of Wales.
The Ancients
End of Ice Age Britain
They cover most of northern England. They just reached down into the northern coast of East Anglia. So if you can imagine a huge glacier, a huge ice sheet going pretty much all the way from East Yorkshire at an angle down to South Wales, that's the extent of the ice sheet and extending into the North Sea Basin beyond. And in front of that ice sheet, there would have been really a polar desert.