Dr. Henry Gee
Appearances
The Ancients
Rise of Humans
Mary Leakey originally thought it might have been a bear because bears can walk upright. But this was really just a blind supposition because fossils of bears are extremely rare. But it's now thought that this was a different kind of hominid. There's a foot, a fossil foot that was found in Ethiopia that looked kind of hominin, but it had a much more divergent big toe.
The Ancients
Rise of Humans
So in other words, its big toe was more like a thumb. And the footprints made by this mystery hominin might have been made by that kind of hominin. So three and a half million years ago, there were bipedal hominins, but some were more bipedal than others. Lucy, Australopithecus aflorensis, walked just like you or I, but probably climbed trees as well.
The Ancients
Rise of Humans
There's some research to show, some forensic pathology to show that Lucy died when she fell out of a tree. So she's got fractures consistent with falling out of a tree. I mean, some people don't believe this, but it's a nice story. So the bipedal chimp phase had a mixture of different species, some of which were better at climbing than others.
The Ancients
Rise of Humans
Well, you know, the thing about paleontology is you must expect the unexpected. So who knows what would come? But I would imagine that when people start looking, if they find deposits of that of a similar age, they will find a greater variety of the bipedal chimp kind of thing until about two and a half million years ago when things kind of changed a bit.
The Ancients
Rise of Humans
It's very hard to say because there were quite a few species of Australopithecus. The first one described, Australopithecus africanus, was described exactly 100 years ago, and that came from South Africa. So that was Australopithecus africanus. And so the paleoanthropology world is celebrating that centenary this year.
The Ancients
Rise of Humans
But there were a number of different species, and whether they were all actually different species or not is a matter of very refined argument. But that genus Australopithecus seems to have been pretty successful throughout Africa. There is another one, indeed, from Chad, Australopithecus bar-el-gazali, which is almost indistinguishable, actually, from Afarensis.
The Ancients
Rise of Humans
And there's another one in, there's some more in Ethiopia, Australopithecus, but there were some later ones and there were some slightly different ones. So there were quite a few of them. Now, whether there'll be a shakedown and they'll all be the same species or not, or whether there'll be more species, it's very hard to say.
The Ancients
Rise of Humans
But certainly, as much as anyone has looked between about five and two and a half million years ago, the Australopithecus model of hominin, which is basically a bipedal chimp, was the kind of hominin that existed on the Earth.
The Ancients
Rise of Humans
It's a big question. I mean, the question is, why did bipedality happen in the first place? It's a really unlikely form of locomotion.
The Ancients
Rise of Humans
And in my new book, which I wanted to call Demure Mindfulness the Taylor Swift Way, but the publishers insisted I called it The Decline and Fall of the Human Empire, I have a whole chapter on bipedality and why it was one of the worst things that could ever have happened to us.
The Ancients
Rise of Humans
Yep, that's right. The human history, well, ancient history, has a very, very long run-up. I mean, recorded history is barely 5,000 years, but this one goes into 98% of human history, which has no written record, and we just pick up from fossils and other scraps of information that we can tell from rock.
The Ancients
Rise of Humans
Traditionally, explanations for bipedality, why we got up and stood on two legs, have been of a kind of after-the-fact reasoning. In other words, we got up on our hind legs to free our hands so we could make tools or carry babies or look over the long grass or show off our gender genitalia to prospective mate or any other idea you can come up with.
The Ancients
Rise of Humans
But these don't actually explain the existence of bipedality in the sense that bipedality is far more than getting up on your hind legs. Various animals can do this, but only for a short time because it's very tiring.
The Ancients
Rise of Humans
And to be bipedal, as a matter of course, requires a complete reengineering of the entire body, from the back of the skull, the curvature of the spine, the internal organs, the valves in the veins in our legs, how our feet are constructed. and all sorts of other things. And bipedality is unbelievably maladaptive.
The Ancients
Rise of Humans
The reason is that for most of the history of backboned animals, our backbone was evolved about half a billion years ago in an aquatic ancestor. And basically, it's a kind of clothesline. It's a kind of clothesline on which the internal organs are hung. So it's basically a beam that's held horizontally in tension. And that's great.
The Ancients
Rise of Humans
But bipeds in the past that were successful, such as dinosaurs, even though they were bipeds, they still held their backbone horizontally. And they were bipeds because they had a very long tail as a kind of cantilever to the trunk. and that allowed them to be bipedal. But humans don't have tails, so we have to do it the hard way.
The Ancients
Rise of Humans
We have to stand the whole body up, change the backbone so it's held vertically in compression. Now, because of this, bad backs are the single most important cause of absenteeism in humans. The vertical state of humans is responsible for edema in the legs, piles, hernias, blue ear in babies. All sorts of musculoskeletal problems are caused by bipedalism. It was a very bad thing.
The Ancients
Rise of Humans
So how did it evolve? Well, no one knows, but the current frontrunner, as it were, is Well, it probably evolved when we were mostly living in trees.
The Ancients
Rise of Humans
Now, apes and monkeys have a variety of ways of getting around in trees, and one of them is kind of a clambering or climbing mode of locomotion, where it's called an orthograde posture, where the creatures basically are climbing in a vertical way among the branches. So I think bipedality is basically climbing among the branches only without the branches.
The Ancients
Rise of Humans
And that's the nearest anyone can get to it. All the other things that have been ascribed to bipedality as an advantage, such as the aquatic ape theory, wading in water, or carrying babies, or making tools, These don't require bipedality to happen. There are lots and lots of very successful ground-living monkeys such as baboons that carry their babies quite well and their quadrupeds.
The Ancients
Rise of Humans
There are monkeys such as capuchins which are quadrupeds that make tools. They just sit on their haunches and do it. Mere cats can stand up and look over the grass and stand on things. So why bipedality happened? What good is it for? Well, it's certainly good for all these things, but it's certainly very bad in many other ways. Also, it's very disadvantageous if you break a leg.
The Ancients
Rise of Humans
Now, everyone's seen three-legged dogs running along quite happily. But, you know, a one-legged hominin, if you broke a leg, you'd be killed. You'd be eaten instantly by some animal. I mean, I broke an ankle in a trivial accident at home.
The Ancients
Rise of Humans
few years ago and i was only rehabilitated thanks to the national health service so i was carted off in an ambulance i will have the administration of surgeons and anesthetists and physiotherapists and a wheelchair alone from the red cross and the long-suffering mrs g to pull me to to push me around in it and a circumstance which definitely led although she denies it to her
The Ancients
Rise of Humans
going back to university to qualify as a nurse, specialising in people with learning disabilities, go figure. But without all these things, I would have died. So natural selection ensured that when hominins started to be bipedal, they had to get very good at it very quickly. Otherwise, so once they started to be bipedal, there was no way back.
The Ancients
Rise of Humans
Yes, 2.5 million years ago or thereabouts was a big change in the Earth climate. It suddenly began to get much cooler than it had been and more seasonal. That's when in the north and far south and in mountain ranges, the ice ages, the sequences of ice ages began to take hold and become more serious. And the result of that was in the tropics,
The Ancients
Rise of Humans
The forest shrunk further, and something opened up this tropical grassland called the savannah, which opened up. And around that time, two new kinds of hominin appeared. One was called Paranthropus, which was a specialist vegetarian. Now, all hominins before that had been kind of scavengers, omnivores.
The Ancients
Rise of Humans
Like chimpanzees today, they would have ate all kinds of things, you know, honey from bees, insects. a bit of plants, nuts, seeds, fruits, maybe some other animals, chimpanzees, hunts and monkeys. And so they would have eaten a bit of everything. But Paranthropus became a vegetarian specialist. It had huge teeth and crunched up fibrous nuts and roots.
The Ancients
Rise of Humans
No, that's the thing about human evolution. The fossils are very uncommon generally, except in certain places. You can count the number of fossils on the fingers of one hand, but the amount of fossils that tell you anything about human origins, you can count on the fingers of one thumb. They are very, very, very tiny, very scarce, mostly teeth like mammals generally.
The Ancients
Rise of Humans
It's known as the robust one, isn't it, or something like that? Yes, they have been called robust Australopithecines, but they're usually classed in their own genus Paranthropus, and there were several of them. And life for them started hard and just got harder and harder. And they became extinct about half a million years ago. The other genus was Homo. That's the genus that includes ourselves.
The Ancients
Rise of Humans
And the first essays in the genus Homo were probably not much different from Australopithecines. In fact, some of them called Homo habilis, Homo rudolfensis. There's been an argument that really these are just other Australopithecines, and I think there's a lot of merit in that. But the first of the genus Homo that really stood apart was Homo erectus.
The Ancients
Rise of Humans
And that originated in Africa over two million years ago. And the reason that was a different thing was it was built entirely differently. Now, all the Australopithecus and the earliest Homo, they had rather short legs and long arms compared to us. And they didn't have much of a neck. Their head was quite, you know, stuck onto the body. And they didn't have a waist.
The Ancients
Rise of Humans
They had kind of a bit of a pot belly. And they were good at walking about. But one thing that Homo erectus could do was run. And Homo erectus was a specialist meat eater. It was a social carnivore, much like hunting dogs, and probably behaved in the same way.
The Ancients
Rise of Humans
Now, a friend of mine, Dan Lieberman, and his colleague, Dennis Bramble, came up with a whole scenario of long distance running as a key feature of the development of Homo. And I'm not surprised. Dan is a very keen ultramarathon runner and runs in bare feet. And he works on human locomotion. So he's really invested in this. But it's the whole syndrome.
The Ancients
Rise of Humans
One thing that Homo has that you don't have except in other predators such as dogs is a ligament that holds the back of the skull to the neck. So it keeps your head up even without effort. Another thing is if you have a neck and if you have a waist, you can keep running with your arms in contra rotation to your legs. In other words, your left arm moves with your right leg and vice versa.
The Ancients
Rise of Humans
And you can keep your neck pointed at where you're looking at, whether it's the finish line of the marathon or the antelope you are chasing. At the same time, humans became more hairless. I mean, humans have the same amount of hair, but it's much sparser. And in between, there are sweat glands that most other animals don't have. I mean, your dogs will pant if they're hot.
The Ancients
Rise of Humans
And animals such as antelopes and cheetahs and that sort of thing, they can run really fast for a short distance. And then they have to stop because they become exhausted and the heat catches up with them. But humans, humans can't sprint very well compared with other animals. But humans are much better than many animals at long distance running. It's the stamina part. Yeah, it's the stamina.
The Ancients
Rise of Humans
It's the endurance. It's the sweating. It's the hairlessness. It's the... the fact that the human cost of transport, in other words, human walking is extraordinarily efficient. This is why just walking about won't lose you many calories, because it's very, very efficient. Running is slightly less efficient, but humans can manage it mile after mile after mile after mile. So
The Ancients
Rise of Humans
Hunter-gatherers, when chasing down some antelope, will chase it for a bit, and then the antelope will stop, and everyone else will stop, and they'll recover. And then the antelope goes on a bit, and the humans chase it. But the humans are relentless, and eventually the antelope will just collapse from heat exhaustion. And this is what happens in real life.
The Ancients
Rise of Humans
But the thing is that humans in the very broadest sense, meaning all our ancestry going back to apes, were always very rare in the landscape. I remember going to East Africa to join an expedition looking for fossil humans living 3.3 million years ago.
The Ancients
Rise of Humans
And there's also a cooperative element, because as you find in many carnivals, like lions and hunting dogs, they kind of, different individuals head them off and ambush them, and one of them flushes it out while the other one jumps on it. This would have been true for Homo erectus as well.
The Ancients
Rise of Humans
So the human body shape that we associate with humans today came with Homo erectus, and it seems to have been associated with a capacity for long-distance running that the earlier hominins didn't have, or at least not as well.
The Ancients
Rise of Humans
Homo erectus is, as far as we know, the first hominin to spread out of Africa and spread all over Eurasia. There are tools from China that are over 2 million years old. There are remains of Homo erectus-like animals or hominins in Spain that are not quite as old. Now, Homo erectus would have no concept of a continent called Africa or that it was leaving it.
The Ancients
Rise of Humans
What they were doing was following the game because the savannah spread all through Africa, all through southwestern Asia and into Europe, right down into Java. So they were following the savannah. So, in fact, Homo erectus was first found in Java by Eugene Dubois. It's in Southeast Asia. Yeah, it was first thought of as a giant gibbon, Pythocanthropus.
The Ancients
Rise of Humans
And it was only when more of the same kind were found in China that Pythocanthropus and Sinanthropus, as it was, were united into Homo erectus, and they were realized to be much more close to humans. Another thing that...
The Ancients
Rise of Humans
put them fairly close to humans in certainly in those days was the was the discovery that homo erectus used fire whether they just used opportunistic bits of fire and carried burning bits around or whether they had learned to actually make fire is a moot point so there's some very exciting evidence that i can't tell you about about the earliest
The Ancients
Rise of Humans
the earliest occurrence of fire starting as opposed to fire usage. But if I told you that, I'd have to kill you. So I can't tell you about that. Not now, not yet. Next time, Henry. But also, Homo erectus made wonderful stone tools, these teardrop-shaped stone tools called hand axes. which are found all over the Eurasia and Africa.
The Ancients
Rise of Humans
in kenya and fossils of alligators catfish turtles were just so common that you didn't bother collecting them occasionally you would find you know a little skull of a fossil pig or a bit of a fossil baboon or a bit of an antelope but in the entire field season the number of fossil human remains were little bits of teeth and jaws that you could fit into a a very small biscuit tin
The Ancients
Rise of Humans
Some are small, some are big, and they're made of different kinds of rock, but that is the signature artifact of Homo erectus. And they may also have scratched scratches on tools, on shells. There are some shells from Eugène Dubois' excavations in Java that show signs of crosshatch scratching.
The Ancients
Rise of Humans
They may also have been capable of some limited watercraft because there are remains of homo erectus, homo erectus certainly there, artifacts in islands in island Southeast Asia that they could not possibly have reached over land even when there were land bridges joining them.
The Ancients
Rise of Humans
So Homo erectus was quite inventive and widespread, but not quite the same as us because, you know, Alan Walker and Pat Shipman in their book, The Wisdom of Bones, which is about Homo erectus. So if we looked into the eye of one, we wouldn't see a human. We'd see a savanna predator. They were very much that. They made tools, but they made tools in a quite different way than we would.
The Ancients
Rise of Humans
And the reason we know that is nobody knows what a hand axe is actually for. So they made hand axes in a very stereotypical way, in the same way that bees make honeycombs or birds make nests. It was a kind of intrinsic thing.
The Ancients
Rise of Humans
Homo erectus, well, you said earlier that, in your opinion, Homo erectus was the most successful hominin, and I would completely agree, because Homo erectus was around from 2.5 million, and the last ones probably died out, maybe 100,000, maybe even more recently in Java. So almost 2.5 million years of very successful hominins.
The Ancients
Rise of Humans
history, which is an incredibly long time for a mammalian species that's generally lived for only a million years. But by that time, Homo erectus had more or less retired to a comfortable retirement home in Java, and its successors were all over Europe. And some of them were big and beefy. I mean, Homo heidelbergensis, which is probably not a real species, but a kind of mishmash of other ones.
The Ancients
Rise of Humans
These were big people. There was a shinbone was discovered at Box Grove in Sussex, which is about the size of a large modern male shinbone, but really thick and beefy. I mean, these people could have played for the British Lions. I mean, they were big people. There were some spears, wooden spears found at Schöningen in
The Ancients
Rise of Humans
In Germany, about 300,000 years old, these were fence posts, and yet they were used as weapons. In East Asia, a marvelous skull was discovered quite recently. There's an amazing story about the discovery of Homo longi, or dragon man. Ah, yes. And the skull, it's only a skull in Manchuria. The skull is at least as big as a modern human.
The Ancients
Rise of Humans
So considering that Australopithecus was only a meter so tall and with a skull of a chimp, you know, these people were big. I mean, you know, like Genesis 6 verses 4, maybe it's Genesis 4 verse 6. I can't remember. There were giants on the earth in those days. But there was more. They were the hobbits. Homo erectus became marooned on islands in Southeast Asia.
The Ancients
Rise of Humans
First, it was known in Flores, which is just to the east of Java. Homo floresiensis. And in the Philippines, these creatures became very small because for reasons that nobody really quite understands, Big creatures marooned on islands become small, and small creatures marooned on islands become big.
The Ancients
Rise of Humans
And that was after months of prospecting. And that was a good year. I mean, it's very rare to find a whole skull or even a whole skeleton. I mean, these are red-letter days.
The Ancients
Rise of Humans
So you have these tiny creatures less than three feet tall fighting off gigantic rats the size of dogs, and huge Komodo dragons, and tiny elephants. And the ones in the Philippines fought tiny rhinos. And they evolved to be very small, but they still made Homo erectus-like tools, only just smaller. And then there was the Neanderthals that they first appeared about 300,000 years ago.
The Ancients
Rise of Humans
And the first signs of them were in Spain. And they tended to be cave dwellers. And they lived in Europe and in Eurasia, as far east as Siberia. and also as far south as the Middle East. But they were cave dwellers. I think that they were built for the rugged extremes of northern Europe in the Ice Age, and they spent most of their time in caves. And they cultivated a deep inner life.
The Ancients
Rise of Humans
There is a remarkable circular structure in a cave in France that was made by Neanderthals. It's a structure of broken stalactites and bear skulls. that is a circle. Maybe it was the foundation of some kind of structure, but it was built in a part of the cave that would always have been away from sunlight, always in total darkness. And Neanderthals are known to have deliberately buried their dead
The Ancients
Rise of Humans
I mean, there are some early signs of some Neanderthal precursors in the so-called pit of bones at Atapuerca, in the Sierra de Atapuerca in northern Spain. It's a pit of bones because the residents chucked their dead ones down this pit at the back of the cave.
The Ancients
Rise of Humans
So that was the first sign of any kind of ceremony, because when animals die, they don't tend to notice the dead ones very much, except if they're perhaps elephants or some other intelligent creature. But Neanderthals actually deliberately buried their dead with flowers and other grave markers. With flowers? Yes, yes.
The Ancients
Rise of Humans
There's a very famous Neanderthal grave at Shanidar in what is now Iraq, where there's signs of concentrations of pollen, which suggests that they marked their dead with their funeral traditions. But some early Neanderthals looked up at the Tibetan plateau and thought, that looks like a nice place.
The Ancients
Rise of Humans
And as they climbed, they evolved into these Neanderthal cousins, the Denisovans, which are Neanderthals. As far as we know, nobody's found much. There's a bit of jaw and some teeth and some hand bones, but they're mostly known from their DNA, which has been extracted. These lived on the roof of the world, which is almost the most inhospitable place you can live, except for Antarctica.
The Ancients
Rise of Humans
And they evolved into these creatures, the genusophans. And we know they evolved at high altitude because... After they evolved at high altitude, they came back down again, and traces of their DNA are found in many people who live in East and Southeast Asia to this day. And a gene from Denisovans is the gene that allows modern Tibetans to breathe easily at high altitudes.
The Ancients
Rise of Humans
So all these Sherpas who go up and down Everest and don't get the credit, they all have these genes from Denisovans that allow them to breathe in low oxygen engines. So that was the Denisovans. So we had these Yetis, and we had the Troglodytes, and we had the Hobbits, and we had these beefy giants.
The Ancients
Rise of Humans
All were the heirs of Homo erectus, and so was Homo sapiens, which originated in Africa at about the same time that Neanderthals originated in Europe.
The Ancients
Rise of Humans
Yes. Modern humans, Homo sapiens, originated as far as we know. I mean, the dates keep being put back and back. The earliest evidence comes from Morocco, from a site called Jebel Irhoud, which has been known for a long time. And every so often, more bones and skulls are dug up.
The Ancients
Rise of Humans
And the latest news from Jebel Irhoud is that there were skulls of something that looked very like Homo sapiens 315,000 years ago or thereabouts. There are other similar skulls from Ethiopia that look a bit like Homo sapiens, but it has to be said that these look pretty rough ingredients. They didn't look completely like modern humans, so they were...
The Ancients
Rise of Humans
they were probably no better or worse living in their environment than any other human. They had to be seasoned by contact with other humans. Now, the modern view of the origin of Homo sapiens is that groups of Homo sapiens would diverge and then come together again and then diverge again throughout Africa for a very long time.
The Ancients
Rise of Humans
Oh, absolutely, for sure. Not only were there likely to be more, but the thing about fossils is fossils is where you find them. And they tend to be more common in some places than others. So people tend to look in the places where they already know fossils tend to be common. So the caves of South Africa have always had top billing. The Rift Valley of East Africa has been a plentiful source.
The Ancients
Rise of Humans
probably interbreeding with other African hominins whose existence we know very little about except in their DNA and also the occasional discovery of bones that are very recent in date but look very archaic. I mean, there's a very famous skull from Iho Eluru in Nigeria that's been known for a long time. It's only 20-something thousand years old, but it looks very, very archaic.
The Ancients
Rise of Humans
And there are other things like that. So there was a great deal of diversity in Africa, a huge amount of diversity. And so there were hominins interbreeding with each other to make Homo sapiens. But at the same time, Homo sapiens were starting to move out of Africa. Now, the first essays in migration in Africa were a bit of a failure.
The Ancients
Rise of Humans
There's Homo sapiens found in Greece that's over 200,000 years ago, but it didn't last. Also, in what is now Israel, there's the Mount Carmel Massif, where Neanderthals and modern humans tended to have a kind of timeshare arrangement with all the caves. In some caves, there are Neanderthals. In some, there are modern humans.
The Ancients
Rise of Humans
And what seems to be the shocker is the modern humans lived there before the Neanderthals did, and they didn't live there that long. So what happens is modern humans tried to get out of Africa, but the Neanderthals had everywhere else kind of locked up. So they didn't compete with them very well, and they probably just visited occasionally in warmer places. spells of climate.
The Ancients
Rise of Humans
But things change because from about 100,000 years ago, maybe slightly more, between 120,000 years ago and 50,000 years ago was quite a warm spell in the Earth's climate. And that's when modern humans in several waves came out of Africa. There were two possible routes.
The Ancients
Rise of Humans
One was through the Sinai Peninsula, and the other was at the other end of Arabia, the Bab el-Mandeb Straits, which might have been much narrower back in those days. But one shouldn't get the impression this was a kind of mosaic exodus. They all kind of decided to go all at once. I mean, it was dribs and drabs. Some were more dribs and drabs than others over a very long period.
The Ancients
Rise of Humans
But as they went, they met the other hominins, the Neanderthals, the Denisovans, and who knows other ones as well. And a lot of the time, they made love, not war. So all modern humans now that do not have an exclusively African descent have about 2% Neanderthal DNA. It used to be more, but natural selection has weeded out deleterious Neanderthal mutations. And so it's about 2%.
The Ancients
Rise of Humans
But we can see evidence for this interbreeding really at the sharp end, because there's a bone of a modern human, a bit of skull of a modern human, about 45,000 years old, that's found in Romania, that had one Neanderthal great-grandparent. So you almost get into those hybridizations.
The Ancients
Rise of Humans
And these hybridizations happened, you know, they weren't often, but they happened enough to leave a strong remnant in our DNA today. So modern humans got into Europe about 45,000 years ago and drove Neanderthals to extinction within 10,000 years. Now, why they drove them to extinction is still a matter of contention.
The Ancients
Rise of Humans
What seems to be the most likely one is you've got to get away from the idea that this all happened all at once. It took several thousand years to happen. It took longer than recorded history to happen. What seems to have happened is that humans, modern humans, were slightly better at raising young to reproductive age than Neanderthals.
The Ancients
Rise of Humans
Humans were slightly less inclined to inbreed than Neanderthals. Neanderthals were very inbred. They lived in much smaller clans than modern humans. Modern humans ranged slightly further over the landscape than Neanderthals. Now, all these things at the time were probably too small to notice, but over thousands of years, these things accumulated.
The Ancients
Rise of Humans
And people have been looking in other places and finding new things in Southeast Asia, for example. And there are quite a lot of very mysterious fossils from China. And places like India have hardly been explored because maybe the relevant rocks are not found. West Africa. It looks likely to be a focus of renewed interest. There are all sorts of interesting stone tools.
The Ancients
Rise of Humans
So it got to a point where hominins have always lived in small groups, but the only way to keep up genetic variation and stop people becoming all the same is occasionally to swap mates with other groups. And what is true in all primates, as far as we know, is that Males tend to stay with the group they were born with, but females tend to move to other groups.
The Ancients
Rise of Humans
And that was true in Australopithecus. We know this from some amazing work on strontium isotopes in bones, which I won't go into. But it's also true in humans and Neanderthals. So you need that interbreeding. Clans would often meet, I guess, at times of festival to drink and swap stories and worship the great gods and also have marriage ceremonies and choose mates, and then they would move around.
The Ancients
Rise of Humans
But when you get to a point in Europe when there were lots and lots and lots of modern human groups and not many Neanderthal groups, the Neanderthal groups were effectively cut off. from other Neanderthal groups. So there are only two things to do, which is become extinct or interbreed with the humans. So that seems to have been the case.
The Ancients
Rise of Humans
It's a similar story in the rest of the world, although not nearly so well documented. It is known that humans met Denisovans and Denisovans met Neanderthals in Eastern Asia. And the same thing happened that the only the Denisovans survive today in a small percentage of DNA, mostly of people who live in Eastern and Southeastern Asia.
The Ancients
Rise of Humans
Papua New Guinea is a very good stronghold of modern Denisovan DNA, which is, you know, Who knows? It was just the lottery of life. The other little ones, like the hobbits, were probably driven to extinction by humans taking over their range, their resources.
The Ancients
Rise of Humans
Now, it's an interesting thing that the hobbits of Flores probably disappeared at about the same time that modern humans arrived there in Flores. And I have this kind of fanciful notion that folk tales of little people living in the mountains are probably folk memories of previous hominins.
The Ancients
Rise of Humans
Now, this is just me being completely fanciful, but I'm, as you know, a great fan of Tolkien, so I think that all the folk tales of elves, dwarves, leprechauns... the little people that lived here before us might have been a distant folk memory of other hominins that lived in the landscape before we arrived.
The Ancients
Rise of Humans
But by 50,000 years ago, all the hominins that had ever lived, and there were many different kinds, had died out except ours.
The Ancients
Rise of Humans
Yeah, well, who knows? By about 40,000 years, yeah, I suppose so. Yeah, 50,000 years ago, there were lots and lots of humans. 40,000 years ago, there was just one. It was just us. And we lived all over the old world. And by the end of the last glaciation, modern humans lived from the Arctic to the tropical forests, and even have moved into the Americas.
The Ancients
Rise of Humans
And only Antarctica, Madagascar, and New Zealand and some oceanic islands had not seen the tread of a human foot. But even those would succumb quite quickly.
The Ancients
Rise of Humans
But one of the problems with West Africa, it is covered in forests, which is very untidy for paleontologists who like to look at deserts where the rocks are more exposed.
The Ancients
Rise of Humans
I think the thing that one has to emphasise, though, is that this is not a tale of manifest destiny. there was nothing written to say that humans would succeed and drive all the other hominins to extinction. I mean, as we've seen, hominins tried to invade Neanderthal territory several times and failed. And another thing, it's about genetic diversity.
The Ancients
Rise of Humans
Neanderthals were unbelievably famey genetically. Now, it's known in Neanderthal history that most of them died out sometime in their history and that their range was recolonized by other Neanderthals from elsewhere. Well, the same is true for Homo sapiens. Humans have always been very, very rare. They've always been one meal from starvation and two or three meals from extinction.
The Ancients
Rise of Humans
They always lived in very, very small groups, which tends to be inbred and very thinly scattered over the landscape. And there have been times, maybe several, where humans have almost died out altogether. There was an episode about... 100,000 years ago, maybe a bit more, when humans almost died out and only lived in refuges in southern Africa, that's actually quite contentious.
The Ancients
Rise of Humans
So there are all sorts of places that people are beginning to look, and West Africa has some very interesting archaeology, that is their stone tools, going back, and there are beginning to be some surprising results coming out of there.
The Ancients
Rise of Humans
But there is genetic evidence for repeated what's called genetic bottlenecks. That means that the population shrinks to a tiny, tiny amount and then reestablishes from that tiny, tiny population. And because there are only a certain amount of genetic variation in that tiny, tiny population, the subsequent population becomes very samey.
The Ancients
Rise of Humans
Everyone looks very similar because it's built from only a limited amount of genetic variation. And way back in hominin history, around a million years ago, there's been some recent work published in Science that described what must have been a very awkward age, about 800,000 years ago, where for a million years, there were only about 1,000 breeding humans at any one time.
The Ancients
Rise of Humans
So there was a long period, and this was before Neanderthals, this was sort of Homo erectus time, but it's looking at the genes of people alive today. There are signs that humans and our immediate ancestors almost became extinct many times. So the fact that we're alive today is really quite remarkable, and the fact that we are not only alive today, but we spread throughout the Earth,
The Ancients
Rise of Humans
with a genetic variability in the entire human species that is no greater than a tribe of chimps living in Côte d'Ivoire today. So we have this extraordinarily low genetic diversity. Maybe we succeeded because Neanderthals didn't, was because their genetic diversity was even worse than ours.
The Ancients
Rise of Humans
It is called The Decline and Fall of the Human Empire, Why Our Species is on the Edge of Extinction. And it's published by Picador in the UK on the 13th of March this year, and in America by St. Martin's Press on the 18th of March.
The Ancients
Rise of Humans
But the biggest surprises of the past 25 years have been in Southeast Asia, where there are a lot of limestone caves, huge numbers of limestone caves that are barely explored. And there is also... Now we can look at the whole genome, the whole DNA of modern people, but also the whole DNA of some extinct species such as Neanderthals. and another species called the Denisovans.
The Ancients
Rise of Humans
We know more about these species from their DNA. And also we find some of the DNA is incorporated into the genes of modern people, such as you and me. Neanderthals particularly, I think, looking at me, I probably have more than you do. But there are some species, human species, which are only known... on bits of DNA in the genomes of living people.
The Ancients
Rise of Humans
It's a bit like identifying Cheshire cats from their smiles. And so there are more. Whether we'll discover more is an open question, but there will be more discoveries. They do tend to happen rather unexpectedly and not very often.
The Ancients
Rise of Humans
Yes, 10 million years ago. Cast your mind back, if you will, to the earth 10 million years ago. There were more forests on the earth. And we're talking about what we used to call the old world, Eurasia and Africa. And there were a lot of apes. There were quite a few apes in Europe and in Africa and in Asia.
The Ancients
Rise of Humans
But some of these were probably more closely related to gorillas and orangutans than to humans. But after that period, the forests tend to thin out. Rather, there was a slow... In fact, since then, there's been a generally slow cooling of the Earth towards the Ice Ages.
The Ancients
Rise of Humans
And in the tropics, the cooling is manifested as forests dying out to be replaced by a more mixed habitat of what you might call savanna or parkland with grasslands and a few trees here and there. And the number of apes diminished, and monkeys became more prevalent. So there were a few apes hanging on. But after about 10, 9 million years, the fossil record of apes almost disappears completely.
The Ancients
Rise of Humans
And so until the turn of this century, there was essentially no record of apes or humans or possible human relatives between 10 and 5 million years ago. None. None at all. And then suddenly, just after 2000, an entire skull dropped right into the middle. It was about 7 million years ago. And this came from Chad in Central Africa, which hadn't been very well explored.
The Ancients
Rise of Humans
And it was an entire skull of a creature called Sahelanthropus chadensis. Sahelanthropus. And it's an unbelievably hard place to work. I mean, it really does look like a blasted desert. And people, I've seen people come, I haven't been there, but I have seen people who've come direct to France, because it was a French and Chad joint expedition.
The Ancients
Rise of Humans
I've seen people come back to France directly from Chad without washing, and they look yellow, they look completely sandblasted. So, but Salampus chalensis was a whole skull, and also there was a couple of elbow joints and a bit of a leg bone that was described later. And these vines, they haven't been directly dated, but there are lots of other animals found there.
The Ancients
Rise of Humans
And looking at the complexion of the fauna, you can tell that it's about 7 million years old. But the interesting thing about Sahelanthropus is it looks like an ape. The skull's about the same size as a chimpanzee. But the hole in the base of the skull, where the spinal cord goes in,
The Ancients
Rise of Humans
is right in the middle at the bottom or almost rather than at the back and that's crucial because a skull that balances on the spinal cord that's on the bottom it comes from an animal that's a biped it walks on two legs if the hole that the spinal cord goes in is at the back of the skull that suggests that the animal is like your sheep or your cat or dog I have a sheep skull here.
The Ancients
Rise of Humans
Here is a skull I prepared earlier. This was a sheep skull I found when I was nine. And if you look, that's the hole where the spinal cord would go in. And it's right at the back of the head. It's right at the back. So if you look at the base of the skull, there's the hole. It's called the foramen magnum, which is Latin for big hole. So let's call it a big hole where the spinal cord goes in.
The Ancients
Rise of Humans
In hominins, that is members of the human family, that hole is moved much further to the center. So the skull would balance on top. And that indicates the one thing that suggests that the owner of the skull was a hominin. And that means a member of the lineage that led to humans as distinct from our closest relatives, chimpanzees. And so Sahelanthropus
The Ancients
Rise of Humans
That was pretty much the only thing that showed that Sir Halanthoffus was a hominin. It looked very ape-like in every other way, but that crucial feature marked it out as closer to living. It's not an ancestor. It's not a missing link. What it means is that it is closer to modern humans than to modern apes. So it is the first sign of something being on our lineage.
The Ancients
Rise of Humans
Yes, I mean, it is central. One of the reasons we can tell is that no other mammal has a skull like that with the foramen magnum underneath. Bipedality, certainly of that style, is absolutely unique to modern humans. I mean, there were an awfully long time ago some apes that tried to be bipedal, but they were kind of bipedal in different ways. They were more definitely apes.
The Ancients
Rise of Humans
But they all died out a long time ago, and there's some rather suggestive footprints that are kind of five million years old. Some people think they belong to bipedal creatures. Some people don't think they're footprints at all. And there were apes that lived much longer ago, 14 million years or so. There's one called Aureopithecus that lived in what is now Tuscany.
The Ancients
Rise of Humans
might have been bipedal, but it died out. But this particular mark of bipedality, the hole, where the position of the hole in the skull is really what marks a hominin, something that is on the human line, as it were, in the human family.
The Ancients
Rise of Humans
Well, the hominin fossil record being very scant, an awful lot of nothing for another two or three million years. The record picks up again about five, between five and four million years in East Africa. There is a creature called Ororin tuganensis from Kenya. That's not known from the skull at all, but it's known from leg bones, which show a bipedal hominin.
The Ancients
Rise of Humans
And there is another creature from Ethiopia called Ardipithecus cadaba, which is about nearly five million years ago. And slightly more recently, Ardipithecus ramidus, which is about four and a half million years old. Ardipithecus ramidus has most of the skeleton. And that's quite interesting. I mean, it's a hominin in that it shows that the move to bipedality wasn't a simple linear thing.
The Ancients
Rise of Humans
Ardipithecus was clearly a hominin and clearly a biped, but not quite as bipedal as you or I. It was probably much better up a tree. It would have been a better climber than us. And it probably, like modern chimps and gorillas do, is they make nests in the lower branches of trees, even though they spend a lot of time on the ground.
The Ancients
Rise of Humans
There are some, even as late as three and a half million years ago, there are a range of different hominins, the bipedal chimp phase. Some were more bipedal than others. There is a series of footprints at a place called Laitoli in Tanzania, discovered by Mary Leakey, this was the great Louis Leakey's wife, back in the late 60s. Did they discover the famous fossil Lucy, Mary Leakey?
The Ancients
Rise of Humans
No, they didn't. That was discovered by other people in Ethiopia, but it's generally thought that Lucy's species, Australopithecus afarensis, was the same species that created the footprint at Laetoli. And certainly from what we know about Lucy's anatomy, that looks... perfectly reasonable.
The Ancients
Rise of Humans
And what we can see from Lucy, because we have a lot of a skeleton of Lucy, what we see from Lucy and these footprints is that these creatures walked as bipedally as you or I, but there are other footprints at Laetoli. What happened in Laetoli was three and a half million years ago, there was a volcanic eruption, as there often are in the Rift Valley, and it rained some ash all over the landscape.
The Ancients
Rise of Humans
And then there was actual rain. So the ash became kind of a bit gloopy and muddy and everything walked all over it. It looked like the Victoria Station at rush hour. There was footprints of all sorts of creatures all over it. So there are antelopes and pigs and And then there's this famous line of Australopithecus afarensis footprints. But there were also some footprints of another creature.