The Ancients - Rise of Humans
Episode Date: April 6, 2025How did we go from ancient apes to the dominant species on Earth? The story of human evolution is one of survival, adaptation, and extinction - stretching back 7 million years.In this episode of The A...ncients, Tristan Hughes is joined by Dr. Henry Gee to unravel the complex origins of humanity. From the first bipedal hominins to the evolutionary leaps that set Homo sapiens apart, together they explore why humans evolved from long-armed tree dwellers to upright walkers and discuss the the advantages that bipedalism gave our ancestors over other species.More from Henry Gee:The Origins of Life on Earth: https://open.spotify.com/episode/3Rb4OcjbmsjIHpFemJ7mmOFeathered Dinosaurs: https://open.spotify.com/episode/05wbG2dMp174D10gP30kIjMore on this topic:Homo Erectus: https://open.spotify.com/episode/3MjgWtiENDpVXc5qv77oTyHuman Evolution: Dragon Man: https://open.spotify.com/episode/128XsUffcThVirTghas7OAPresented by Tristan Hughes. Audio editor is Aidan Lonergan, the producer is Joseph Knight. The senior producer is Anne-Marie Luff.All music courtesy of Epidemic SoundsThe Ancients is a History Hit podcast.Sign up to History Hit for hundreds of hours of original documentaries, with a new release every week and ad-free podcasts. Sign up at https://www.historyhit.com/subscribe. You can take part in our listener survey here: https://insights.historyhit.com/history-hit-podcast-always-on
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It's The Ancients on History Hit. I'm Tristan Hughes, your host.
Today we're covering the rise of humans.
Yep, that's right, human evolution.
It's a story that stretches back some seven million years, one that begins with ancient apes
and ends with us, with many different species of early humans emerging and disappearing in between.
The story of human evolution is one still shrouded in mystery.
Not only is the fossil record for early humans extremely limited, but so much of it is still debated. Including the all-important
question, why did early humans, or hominins, why did they become bipedal? How did they
evolve from long-armed tree dwellers to two-legged runners? These radical changes in bodily structure
that have occurred over millions
of years.
Joining me to talk through this evolution story is a fan favourite of the podcast, Dr
Henry G. Henry has been on the podcast before to talk about both the origins of life on
Earth and the dinosaurs. Quite a few of you have been clamouring for us to have him back
on the show and I'm delighted to announce his return to talk about the fascinating story of The Rise of Humans.
Henry, welcome back to the podcast. It has been too long.
Thank you very much, Tristan.
We've done Top 5 Dinosaurs, we've done the wonderful story of the origins of life on Earth,
and this feels like another story, the Rise of of humanity. And Henry, this is a story we need to start with. It takes
us back more than five, six, seven, eight million years. There's a lot of history and
ancient history and prehistory to cover here.
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.
And to tell the story of human evolution, as we're going to be covering several million years of history, you mentioned fossils. How rich a record do you have for studying human evolution? Do
you have many examples of fossils from millions of years ago surviving?
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.
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
in Kenya.
And fossils of alligators, catfish, turtles
were just so common that you didn't bother
collecting them. Occasionally you would find a little skull of a fossil pig or a bit of
a fossil boon 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 very small
biscuit tin and that was after months of prospecting.
That was a good year.
It's very rare to find a whole skull or even a whole skeleton.
These are red letter days.
So we are going to be covering several different early human species as this chat goes on.
But with that kind of sparsity of surviving evidence do we think that there were probably many other species on the human line that we just don't know about.
Oh absolutely for sure not only were there like 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 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 there are the relevant rocks are not found. West Africa,
it looks likely to be a focus of renewed interest. There are all sorts of interest in stone tools,
but one of the problems with West Africa, it of interest in stone tools. One of the problems
with West Africa is that it is covered in forests, which is very untidy for paleontologists
who like to look at deserts where the rocks are more exposed. 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.
But the biggest surprises of the past 25 years have been in Southeast Asia, where there were
a lot of limestone caves, huge numbers of limestone caves that are barely explored. 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 On bits of DNA in the genomes of living people it's a bit like identifying Cheshire cat from their smile and so there are more weather will discover the mall is open question but there will be more discoveries they do tend to happen rather unexpectedly and not very often.
and not very often. Right, Henry, now let's delve into the story. We are sitting comfortably.
When does the human story begin? We go back to apes, I'm presuming.
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 but some of these were probably more closely related
to gorillas and orangutans than to humans. But after that period, the forests enter 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. 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.
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. And so between until the turn of this century, there
was essentially no record of apes or humans or human and possible human relatives between
10 and 5 million years ago. None, none at all. And then suddenly in just after the 2000,
an entire skull dropped right into the middle. It was about 7 million years ago. And then suddenly in just after 2000, an entire skull drops right into the middle.
It's about seven million years ago. And this came from Chad in central Africa, which is
hadn't been very well explored. 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 Chad joint expedition.
I've seen people come back to France directly with from Chad without washing and they look yellow.
They look completely sandblasted.
Chad without washing and they look yellow, they look completely sandblasted.
So the Salon plus Chadensis 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 finds are, they haven't been directly dated,
but looking at the, there are lots of other animals found there and looking at the complexion of the fauna, you can tell that it's about seven million years old.
But the interesting thing about Sahelanthus is it looks like an ape, the skull is about
the same size as a chimpanzee, but the hole in the base of the skull where the spinal
cord goes in is right in the middle at the bottom or almost rather than at the back. the of the skull that suggests that the animal is like your sheep or your cat or dog.
I have a sheep skull here.
This is Henry is standing up to fetch the sheep skull which is right above his office
setup.
Here is a skull I prepared earlier.
This is a sheep skull I found when I was nine.
And if you look that's the hole where the final cord would go in.
And that's right to the back of the head.
Right at the back.
It's not 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 it's just called a big hole where the spinal cord goes in
in hominins
that is members of the human family
that hole is moved
much further to the centre
so the skull would balance on top
and that indicates the one thing 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, that was pretty much the only thing that showed that Sahelanthropus
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. A distant
great uncle, let's call it.
It's amazing how the earliest evidence you have, say 7 million years ago, found in a
remote corner of Chad. And even though you don't have the full body surviving or all of the legs,
just from that skull and the position of the spine, you can deduce that it is different
in its locomotion in bipedality, which is central, isn't it, to the whole story of
the rise of humans?
Yes, I mean, it is central. One of the reasons we can tell is that no other mammal has a the rise of humans 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, 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 belong to bipedal creatures. Some people don't think their footprints at all.
And there were apes that lived much longer ago, 40 million years or so in there's one
called Aureopithecus that lived in what is now Tuscany that might have been bipedal,
but it died out.
But this particular mark of bipedality that the whole weather position the whole of the skull is really what marks marks a hominid something that is on the human line as it were in the human family.
dawn of the bipedal chimps phase. So what comes next following Sahelanthropus in the millions of years and in the story of the rise of humanity?
Well, the hominin fossil record being really scanned an awful lot of nothing for another
2 or 3 million years. The record picks up again between 5 and four million years in East Africa.
There is a creature called Orynthuginensis from Kenya.
That's not known from the skull at all, but it's known from leg bones, which show a bipedal hominin.
And there is another creature from Ethiopia called Ardipithecus cadabra, which is about nearly five-ish million years ago.
And slightly more recently, Ardipithecus ramidus, which is about four and a half million years old.
Ardipithecus ramidus has most of a skeleton.
And that's quite interesting. I mean, it's a hominin in the it shows that the move to bipedality
wasn't a simple, a simple linear thing. 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.
So there are some that even as late as three and a half million years ago there were a
range of different hominins, the bipedal chimps face, some were more bipedal than others. the discovered by other people in Ethiopia, but it's generally thought that the species that
Lucy's species, Australopithecus afarensis, was the same species that created the footprint at
Lytoli. And certainly from what we know about Lucy's anatomy, that looks perfectly reasonable.
And what we can see from Lucy, because we have a lot of a skeleton of Lucy,
and these footprints is that these creatures walked as bipedally as you or I,
but there are other footprints that light only.
What happened in light only 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. 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 were footprints of all sorts of creatures all over it, so there were antelopes and pigs.
And then there's this famous line of Australopithecus
afarensis footprints. But there were also some footprints of another creature. 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 hominin.
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.
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 aflurentis walked just like Uribe but probably climbed trees as well.
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.
Well Henry it's interesting because obviously we've started with Sahelanthropus and then covered
Ardipithecus and then Australopithecus which feel like the big names you need to cover in that early
phase that bipedal chimp phase and yet we've gone from seven million to three million years or 3.5
million years. So that's almost half the whole story of human evolution that we know about and yet the evidence that we have surviving.
Is quite red only know a handful of different species just for example that big gap between so highland persons are the pithicus that you highlighted between seven and four million years ago.
That's two to three million years in between that the evidence is lacking and it'd be fascinating to know kind of hopefully in the future more evidence will emerge learning a bit about that whole evolutionary step diversity 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.
And so we get to Australopithecus, and I know of Australopithecus,
there are various almost subspecies of Australopithecus and I know with Australopithecus there are various almost subspecies
of Australopithecus found all across Africa. We're still centred in Africa at this moment
in time. But would you argue are they the most successful in the bipedal chimp phase?
Are they the most bipedal of them all too?
It's very hard to say because there were quite a few species of australopithecus.
The first one described, australopithecus africanus, was described exactly a hundred
years ago and that came from South Africa. So that was australopithecus africanus and
so the paleoanthropology world is celebrating that centenary this year. But there were a the pretty successful throughout Africa there is another one in deep and Chad off the be the same species or not or whether there'll be more species it's very hard to say but certainly as much as anyone who's looked between about five and two and a half million years ago the australopithicus model of hominin which was basically a bipedal chimp was the kind of hominin that existed on the earth.
a bipedal chimp was the kind of hominin that existed on the earth.
And it's also interesting that you've got Anamensis, Sadeba, Africanus, as you mentioned, all these different types of Australopithecus. Just imagining them walking around strutting their
stuff, maybe the people who left those footprints at Laetoli, as you mentioned, those original
footprints found by Mary Leakey and her team. If it seems that these
bipedal chimps, by the time we get to Australopithecus, they're becoming more capable
of being bipedal and they're almost walking like we would do, at least for some stages,
the big question is why? Why do you think these early hominins, they start becoming more and more
bipedal? 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. In my new book, which I wanted to call
Demure Mindfulness, the Tailor Swift Way, but the publishers insisted I called it
The Decline and Fall of the Human Empire, I have a whole 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. 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 you can come up with, 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. matter of course, requires a complete re-engineering 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 reason is that for most of the history of backboneed 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, 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. 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. How did it evolve? Well,
no one knows, but the current front runner, as it
were, is well, it probably evolved when we were mostly living in trees. Now, apes and
monkeys have a variety of way of getting around in trees. And one of them is kind of a kind
of clambering or climbing mode of locomotion, where it's called an orth grade posture where the creatures.
The creatures basically are climbing in a vertical way among the branches so I think by fidelity is basically climbing among the branches only without the branches.
I'm not the that's the nearest anyone can get to it all the other things that have been described to buy 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 they're quadrupeds.
There are monkeys such as capuchins,
which are quadrupeds that make holes. They just sit on their haunches and do it.
Meerkats 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. Now, everyone's seen three-legged dogs running along quite happily, but a one-legged
hominin, if you broke a leg, you'd be killed. You'd be eaten instantly by some animal. I
broke an ankle in a trivial accident at home a few years ago and I was only rehabilitated thanks to the National
Health Service.
I was carted off in an ambulance, I will have the administration of surgeons and anaesthetists
and physiotherapists and a wheelchair, a loan from the Red Cross and the long-suffering
Mrs G to pull me to push me around in it and a circumstance
which definitely led, although she denies it, to her going back to university to qualify as a nurse
specializing 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. So once they started to be bipedal
there was no way back and so that's why you get all these bipedal hominins around that time.
It's interesting, it's such a key stage in the story of evolution. And thank you for
explaining out there, Henry, the importance of that change in the backbone and bipedalism.
So we have got to, let's say, about 3, 2.5 million years ago. And it feels like this
is when the next overarching phase comes in, the beginning of the genus that we belong
to, the homo genus, the homo phase begins. 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, forests shrunk further and something opened
up this tropical grassland called the savanna, 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 have been kind of
scavengers omnivores like chimpanzees today they would have 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.
It's known as the robust one, isn't it, or something like that?
Yes, it was. They have been called robust Australralopithecines but they're usually part class 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 they they became extinct about half a million years ago.
The other genus was homo that's the genus that includes ourselves.
that's the genus that includes ourselves and the first essays in the genus homo were probably not much different from austral epithecines in fact some of them called homo habilis, homo rudolfensis, there's been an argument that really these are just other austral epithecines and there's a lot of merit in that. But the first of the genus Homo that really stood apart was Homo erectus and that originated
in Africa over two million years ago.
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
arm compared to us.
And they didn't have much of a neck, their head was quite stuck onto the body, and they
didn't have a waist, 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.
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 surprised Dan is a very
keen ultra marathon runner and runs in bare feet. So and he worked on human locomotion.
So he's really invested in this. But it's not it's the whole syndrome. 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 for 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 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.
Humans have the same amount of hair, but it's much sparser.
In between, there are sweat glands that most other animals don't have.
Your dogs will pant if they're hot 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 they 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 the 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 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. This is what happens in real life. 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.
So the human syndrome of 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.
I mean, Henry, it's no surprise then it's no coincidence that
homo erectus literally translates as upright man.
That's correct.
Yeah.
And I remember doing an interview with John McNabb a couple of years ago on Homo erectus.
And he showed me a replica pelvic girdle of Homo erectus. And it's basically exactly
the same as a modern human. So as you say, this was a fully bipedal early human built
for running covering long distances, which leads us very nicely into the next big question
with Homo erectus, which is how far and wide does Homo erectus ultimately spread? Because
we've been talking only about Africa so far in our chat.
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. What they were doing was following the game because the savannah spread all through Africa, the the south east Asia, the other thing that the the shaped stone tools called hand axes, which are found all over the Eurasia in Africa.
Some are small, some are big, when they're made of different kinds of rock, but that
is the signature artifact of Homo erectus.
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.
They may also have been capable of some limited watercraft because there are remains of Homo erectus, certainly their artifacts,
in islands in Southeast Asia that they could not possibly have reached over land even when there were land bridges joining them 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. 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 nets. It was a kind of intrinsic thing.
Homo erectus is one of, if not the most successful I would argue, and longest lasting of early humans, isn't it? And it's a fascinating story, if anyone wants to learn more about
the story of human evolution, you start at Homo erectus because it is such a central
hominin to learn about in the ultimately the emergence of Homo sapiens and all of that.
And I wish we could cover so many different examples, but Henry, set the scene just before the arrival of Homo sapiens onto
the main stage. How many different types of early humans are there and how diverse are
they?
Henry V.
Henry 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 one the 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
Homo heidelbergensis, which is probably not a real species, but a kind of mishmash of other ones.
These were big people. There was a shinbone
was discovered at Boxgrove 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 Germany about 300,000 years old.
These were fence posts and yet they were they were used as weapons in East Asia.
A marvelous skull was discovered quite recently.
There's a amazing story about discovery of homo longi or Dragon Man.
Ah, yes.
And the skull is only a skull in the Manchuria.
The skull is at least as
big as a modern human. So considering the Ostalopithecus 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 six
versus four, maybe it's Genesis four versus six, I can't remember it. 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. 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 small and small creatures marooned
on islands become big.
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,
and the first signs of them are 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.
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.
There is a remarkable circular structure in a cave in France that was made by Neanderthals.
It's a structure of broken stalactites and bare skull 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 deliberately buried their dead.
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.
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. So with flowers. Yes, yes, there's a very famous neanderthal grave at shanid are in that what's now iraq where the signs of concentrations of all of them
the which suggests that they buried their dead with with they marked the date with with that funeral and looked up at the Tibetan plateau and thought, that looks like a nice place.
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.
And they evolved into these creatures, the Denisophans.
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 altitude.
So all these Sherpas who go up and down Everest and don't get the credit, they all have these genes from Dennis ovens that allow them to breathe in low oxygen engine so that was the Dennis ovens so we have these yet is and we have the chocolate ice and we have the hobbits and we have these beefy.
Africa at about the same time that Neanderthals originated in Europe. Yes Henry so let's get on to now the final chapter almost the arrival of homo sapiens onto the onto the scene and interactions with all of these other early human species that it must have shared the world with for hundreds of thousands of years before ultimately becoming the last one standing. 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 Ehud which has been known fors 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 probably no better or worse living in the
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, 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.
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 into breeding with each other to make Homo sapiens.
But at the same time, Ho sapiens were starting to move out
of Africa. Now, the first essays in migration in Africa were a bit of a failure. There are
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.
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.
Bells of climate, but things change because from about a hundred thousand years ago,
maybe slightly more between 120 years, thousand years ago and 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.
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.
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 of natural selection has weeded out deleterious Neanderthal mutations,
and so it's about 2%.
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, 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.
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. 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 accumulate. 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 and that's true that was
true in Ostrum Apithecus we know this from some amazing work on strontium isotopes in bones which
I won't go into but it's also true it's also true in humans and Neanderthals so you need that
interbreeding clans would often would meet I guess at times of festival to drink and swap stories and worship
the great gods and also have marriage ceremonies and choose mate and then they would move around.
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. The Neanderthal groups were effectively cut off from other Neanderthal
groups. So there were only two things to do, which is become extinct or interbreed with the
human. So that seems to have been the case. 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,
Papua New Guinea is a very good stronghold of modern Denisovan DNA, which is, you know,
who knows, it's 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. 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 motion that folk tales of little people living in the
mountains are probably folk memories of previous hominins. Now, this should just be being completely
fanciful, but I'm, as you know, a great fan 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
but
by 50 000 years ago
All the hominins that have ever lived and they were many different kinds had
died out except ours.
Do you mean by 40,000?
Yeah, it's well, who knows exactly, 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 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.
It makes you realise also, doesn't it, for those of you listening in from North America
or South America, actually how late in the story of human evolution humans do actually
cross that Bering land bridge into the Americas because we focus largely on Eurasia and Africa
today, but that's another interesting part of the chat and we've done episodes on the
first Americans before. We've also done an episode with the one and only the Oracle
of Neonatal Studies Professor Chris Stringer. He basically says quite similar to you Henry
about you know how the Neonatals die out that lack of genetic diversity and basically homo sapiens
are just a bit better at all of those important things that endure over time. I've got a paragraph
from your book which feels good to read out now, it's only a sentence, actually a couple
of sentences. As you say, by 40,000 years ago at the latest, Homo sapiens was the last
hominid on earth. In just a few geological eye blinks, it had not only eliminated all
the other hominids, but it spread to every part of the earth and as a bar Madagascar,
Antarctica, New Zealand and the Pacific Islands.
It's a huge journey isn't it having gone from seven million years ago in Sahel Anthropos and the first of those bipedal chimps that we know of.
Two homo sapiens to us today.
I mean what a journey it has been I mean not for us personally but but the whole story of human evolution.
I think the thing that one has to emphasize 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 is about genetic diversity. 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 re-colonized 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. 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, 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.
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 a thousand breeding
humans at any one time. So there was a long period and this was before Neanderthals,
this was sort of Homo erectus time, but it's talking, 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
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 the antithels didn't, it was because their genetic diversity was even
worse than ours.
ALICE Henry, you do cover that kind of humans today as well in this new book, which is called,
it's not the Swiftig-Eden book, title it is called, Henry?
HENRY 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 Martin's Press on the 18th of March.
Well, Henry, it just goes to me to say thank you for coming back on the podcast today.
Thank you very much.
Well there you go, there was fan favourite guest Dr Henry G returning to the ancients to talk
through the story of the rise of humans. I hope you enjoyed the episode. If you want to listen
to the other episodes which feature Dr Henry G, well then check out in our archive our episodes on the origins of life on earth, there's another
one called Top 5 Dinosaurs where Henry and I talk through our top 5 including the brilliant
species that was the iguanodon with its thumb spikes and another episode, another of Henry's
pet favourite topics which is the story of feathered dinosaurs which has really come
to the fore in the last couple of decades of scientific research.
Thank you for listening to this episode of the ancients. Please follow this show on Spotify
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