The Other Sapiens— what happened to the primitive humans who lived alongside us?

Added: 2026-05-28

[00:00:00]Tens of thousands of years ago, Homo sapiens was part of a remarkably diverse evolutionary tree, one with many different lineages.

[00:00:10]And we are the only branch of that evolutionary tree that still exists, the sole survivors.

[00:00:16]Who were these other humans and what happened to them?

[00:00:21]Today, I'm going to talk about the other homo sapiens.

[00:00:25]And the story of their disappearance is a part of the story of where we come from.

[00:00:33]On the western slope of Mount Carmel in northern Israel lies the cave of Eskull.

[00:00:40]Around 120,000 years ago at the high heel of the last ice age, nomadic hunter gatherers made camp here. The sea to the west had receded, exposing a broad plane covered with groves of live oak, meadows of asphodel and anemone.

[00:00:55]Herds of deer, rhinoceros, and oroxs roamed the plains. And people would hunt these animals with stone tip spears and would forge for almonds and olives and wild mustard.

[00:01:08]We know all this because when these people died, they buried their dead by the mouth of the skull cave.

[00:01:14]And the skeletons found here represent some of the earliest known members of our species, Homo sapiens. But these homo sapiens were very unlike us. They were a very different Homo sapiens.

[00:01:27]Skull Cave was first excavated in 1929.

[00:01:30]Parts of 10 skeletons, 10 different burials were eventually found. Soon after the remains of 28 people dating to around 90,000 years ago were discovered near Nazareth at nearby Kafsa Kafsa cave. And when they were first found, the Schol and Kafsa remains were among the oldest known Homo sapiens. And today, a century later, they still are.

[00:01:52]And yet, remarkably, almost 100 years later, we're still not entirely clear where they fit into the picture of human evolution and their relationship to modern humans.

[00:02:04]So, this is a specimen from the fifth grave at Schol. So, it's known as Skull 5. And it shows this really curious mixture of advanced and primitive characteristics. So some features are very advanced, very modern like us and others are more primitive like Neanderthalss.

[00:02:20]And overall it has a lot of modern human features that we don't see in the Neanderthalss, but it's just far far more primitive than what we see in living homo sapiens. It's not truly modern.

[00:02:33]Now Skull 5 and other specimens from Skull and Kafsa show advanced features relative to Neanderthalss in a number of different ways.

[00:02:45]So one thing we see is the skull is overall shorter and the brain case is more strongly domed. Neanderthalss have this kind of elongate skull kind of more like an American football or a rugby ball versus the more kind of soccer ball or volleyball shape that you get in homo sapiens. Uh and so this thing is more modern in that respect. The chin is also stronger. Neanderthalss have a very very weak chin. The tooth row is shorter. So in all of these features, the specimens that we see at Scholola and Kafsa are more like modern humans than Neanderthalss are. And that allies them with us. So they've traditionally been assigned uh in recent years to Homo sapiens.

[00:03:28]However, the skull of modern humans are even more advanced than these specimens that we see at Schol and Kafsa. They have an even shorter, more strongly domed, more bubble-shaped skull. Again, this very round kind of soccer ball shape. The jaw is even shorter. The teeth are smaller. The chin is much stronger and very strongly projecting.

[00:03:48]That is a unique feature of Homo sapiens that modern Homo sapiens take to a greater degree of development as that very strong chin. So, in all of these features, they're these specimens that we're seeing 100,000 years ago are more primitive than we see in modern humans almost anywhere in the world.

[00:04:06]We can also see this in anterior view.

[00:04:09]You see that the archaic or the ancient homo sapiens that we find in skullsa have this lower broader skull. It's not as tall and strongly domed. Uh the nostrils are much wider. These guys had big noses. They have these really massive wide jaws. And in a modern homo sapiens, you have this very tall, highly domed brain case, narrower upper and lower jaws, and a narrower nose. So and again what we're seeing is that this is homo sapiens that we're finding here at scholenafsa but it's more like Neanderthalss in a number of features than modern humans are.

[00:04:44]So these guys just how human are they? We also have some artifacts from these specimens and they also show this kind of mixture of fairly modern characteristics and more archaic features. So the artifacts associated with these people are part of a tool tradition known as the Mustion and Mustion technology is advanced compared to the relatively primitive aulian tools like the hand axes used by early Neanderthalss but it's more primitive than what we'll see uh in modern homo sapiens like promagnon man where you have things like bows and spear throwers and things like that. The skull and Kafsa people have abandoned this achilian handax technology for smaller stone tools. They would strike off flakes and blades off of these disshaped stone cores. They make these big triangular spear points called mustisterian points. And they're made using a flintnapping style calling called the levelwa technique where you prepare a stone core and you strike off in a single motion. You strike off a big blade that you then turn into a spear point. And these are then hafted onto throwing spears to hunt big game and probably to kill other people as well.

[00:05:52]Uh and curiously the mysterion tools are adopted by later Neanderthalss which raises some interesting question. Did these homo sapiens get their tools from Neanderthalss or vice versa? Are Neanderthalss picking up their technology from these early and primitive homo sapiens?

[00:06:08]We can also tell something about these people by some of the artifacts they left behind. Uh some artifacts that are surprisingly remarkably wonderfully human. And we see it both the Schol locality and Kafa that they would take seashells uh little snail shells, little clamshells, and they'd punch holes in them and they're making them into beads for necklaces or bracelets perhaps. And at least in the case of Casa, it would have been pretty far from the sea at the time because the sea levels were lower.

[00:06:39]It was about 30 miles away from the sea.

[00:06:42]So either they're wandering over huge distances or they may have been trading to get these. and trade is a very human thing that we don't see as much evidence for in Neanderthalss. So, we're seeing some features uh that are are surprisingly humanlike in their in their in their associate archaeological remains.

[00:07:01]Now, these burials are also very interesting and they are burials. Uh they, you know, they were dug into holes and left there and there there's a sort of a series of features that show these are burials and just not natural deaths.

[00:07:13]One thing is the bodies show this consistent position. They're always found curled up on their sides and they're also consistently associated with cave mouths and that suggests there's some sort of spiritual belief uh that is associated with these burials.

[00:07:28]And we don't really know what that belief was. But what's really remarkable is that this pattern of burial where people are buried near cave mouths on their sides is very consistent and it's found in burials between these two localities that span a period of something like 20,000 or 30,000 years which makes it one of the longest traditions we know of in the archaeological record. They had some belief associated with death and burial.

[00:07:52]And not only did they have this belief, this belief was passed down from generation to generation for tens of thousands of years, which is really remarkable when you think about it. The extraordinary persistence of this culture. We also see some very interesting things uh relating to these burials. We see ochre pigments that are typically used for painting uh associated covering these skeletons. So there's ochre covering the graves and this uh iron oxides pigments. And remarkably, we also see several skeletons that were associated with grave goods.

[00:08:28]A man buried at Schul has a boar's jaw on his chest and a teenage boy at Kafsa is buried curled up clutching the antlers of an elk. And the meaning of this practice is unclear. You know, maybe these artifacts were trophies.

[00:08:43]Maybe they're charms or offerings. Maybe they provided some protection or help to the spirits of the dead. Maybe this is some way that people had remembering these people. You remember that great hunt where we got the boar? You remember that time you killed the elk? And maybe they wanted these memories somehow to be, you know, associated with these these graves. Uh but quite likely some sort of spiritual significance to it.

[00:09:05]And the burials themselves hint at some idea of an afterlife or some sort of spiritual beliefs. And the fact that so many bodies are found in very small areas shows that they were doing this repeatedly coming back there over and over and over. And there's there's a lot of caves out there that have never been dug as well. So it's quite likely I suspect it's not like they they dug up a 100 different caves to find these these two sites. There's relatively few that have been well excavated and there are other sites in the area that you know I suspect if we dug in we might find more out there.

[00:09:37]So these sites were clearly important to them for for some reason.

[00:09:41]Um, you know, this is kind of speculative a bit, but maybe the loved ones brought their dead to the caves to join the ghosts of their ancestors. And I I know this might sound like kind of speculation, but you know, the Hodz tribe of Tan Tanzania, I've talked to these guys, and they believe the caves have a spiritual significance, and the caves are sometimes used as shelters, uh, as rock shelters, but they're also associated with what they call the Galan Bay, the ancestors, the ancestor spirits. And people will go to these caves uh in in the Hodzab will go to the caves to commune with their god. They'll make offerings of meat and honey and they'll pray for game and for rain. And when people die, they will bring their bodies there to these caves. So it's entirely possible these people had a similar belief. I'm just saying here's a modern tribe that that brings their bodies to caves and these are the belief systems associate with that. It's entirely possible that a similar type of belief system was already in existence over 100,000 years ago.

[00:10:41]So who were these people? Uh these people who show features of us but also retain more permanent features associated with Neanderthalss.

[00:10:50]These people are so mysterious we don't even know what to call them. And archaeologists have sometimes called the people of Schul and Kafsa anatomically modern humans.

[00:11:02]They love that term anatomically modern humans. And you know, it's it's all kind of bit relative uh in a relative way.

[00:11:09]They are modern. They're certainly more modern than Neanderthalss. They're a lot more, you know, like us than than they are Neanderthalss. A lot of features, but I think that they're kind of overplaying their hand by calling them anatomically modern. They're kind of more modernish.

[00:11:25]I think we are so desperate to understand our origins and we have so few good remains of truly modern humans, which we'll I'll get to that in a bit, that there's been this tendency to seize on anything remotely like us and call it modern and saying that it relates to our ancestry. Uh, but I think the term anatomically modern is doing a lot of work here. I think the term anatomically modern humans is a bit misleading.

[00:11:54]I prefer to call these guys archaic homo sapiens. And this acknowledges both their length to modern people. They're part of our species, homo sapiens, but also there's this gap between them and living humans. They're not fully modern. They're like us, but not completely.

[00:12:12]Alternatively, we might just call them the other sapiens.

[00:12:19]Since the discovery of the Scho site, archaic homo sapiens have been discovered elsewhere in the Middle East, in Africa, and and even in Europe. And as often happens in science, more data has, if anything, deep in the mystery.

[00:12:35]And the story turns out to be remarkably complicated.

[00:12:40]So the Flores bad skull uh we found in archaic sapiens in South Africa. This is significantly older than those of Israel and they date to something like a quarter of a million years ago, 259,000 years ago, plus or minus. And this site is from near Florisbad in central South Africa.

[00:13:00]We've also found archaic sapiens in East Africa along the edge of an alkali lake, Lake Yasi in northwestern Tanzania. Uh this is near where the Hodzabay hunter gatherers, some of the last living hunter gatherers still live today, a little south of Serengeti. Uh the dates on these are not really well constrained, but maybe something like 120,000 years ago or more. We have archaic sapiens on the edge of Lake Yasi.

[00:13:26]We've also found archaic sapiens from two different sites in Ethiopia. The Herto skull comes from the Herto unit of the Bore formation dates to around 157,000 years ago. Then we have the OMO one and OMO 2 skulls from the Omo Kibish site along the Omo River in southwest Ethiopia. These date to around 233,000 years ago.

[00:13:50]The oldest known archaic sapiens actually come from North Africa from Jebel Hood in Morocco and these date to around 315,000 years ago. Curiously, Morocco has also produced some of the youngest known homo sapiens, archaic homo sapiens.

[00:14:08]So, skulls found at Darus Sultan near Rabat date to around 100,000 years ago.

[00:14:13]And exactly where they fit in is a little unclear because they are in a number of ways more modern, more sapiens than Jebel Hud is. Uh the skull is much more strongly domed. And so I I'm kind of speculating, but maybe they're more closely related to people like Scholan Kafsa than they are actually a jabler or her hood in Morocco. Although brow ridges on these things are just absolutely massive.

[00:14:34]And these remains are found these distinctive tanged spear points called points. And these points which seem to be kind of a good indicator of these people are only found in association with archaic homo sapiens in northern Africa not with more primitive species not with fully modern homo sapiens. And these spear points show up to as recently as something like 20,000 years ago and Morocco and Western Sahara showing these guys survived until surprisingly recently in Morocco in northwest Africa.

[00:15:06]And then we have remains from a site called Io in Nigeria in West Africa. And these date to as recently as something like 14,000 years ago.

[00:15:19]So surprisingly, it turns out that these archaic homo sapiens also got into Europe. So they got not only did they get out of out of Africa into the Middle East, they show up in Europe. uh we have an archaic form of homo sapiens emerging into Europe before the main out of Africa migration that gives rise to Eurasians and Native Americans and Australians. So we found an archaic sap skull at Apadema cave in Greece. I want to say that dates something like I think close to 200,000 years ago.

[00:15:51]And then we have even more recently kind of sort of out of nowhere, we have teeth of archaic homo sapiens showing up briefly and they're bracketed by Neanderthalss.

[00:16:04]So there's Neanderthal teeth. Then these modern these archaic homo sapiens show up, more modern Neanderthalss, but not fully modern. And then Neanderthalss show up again, kind of replacing them again. And this is a site called Grat Mandra in France. And um it's very very sparse remains again just a few teeth but you can do these complex you know these do these multivaried analyses of shape analyses and cluster analyses and these teeth plot out with the skolenasa people rather than modern homo sapiens or neanderthalss. So it seems like there's an archaic sapiens showing up all the way in western Europe uh something like a little little over 50,000 years ago. And so again, it seems like there's an initial out of Africa radiation before the main radiation. It gets all the way to Western Europe and then just kind of disappears just mysteriously. They're there. They show up, displace the Neanderthalss, and then Neanderthalss move back in and replace them.

[00:17:08]So when you kind of put all this together, the picture that emerges is pretty striking. uh you know we think okay these are primitive homo sapiens archaic homo sapiens but they're they are also the most successful homo sapiens of their time uh they're not just common they are the most widespread abundant and successful humans of their time they are the most successful you know they're far more successful than modern homo sapiens they're everywhere and they were probably the most you know dominant human species you know more so than neanderthalss or doans Now archaic sapiens are widespread across Africa and they would have had access to abundant big game and plants to forage. Uh so they must have greatly outnumbered the Neanderthalss.

[00:17:55]Neanderthalss are restricted to Europe which is a much smaller area. It's a more hostile area. Uh it's got long winters, just don't have the same abundance of game and food that you would have plants to forage that you would have in Africa. So I mean remember Africa is just absolutely enormous when you see it on a globe or an equal area map. uh Mercury projections don't really show just how how incredibly huge Africa is. So it's possible that archaic sapiens I mean it would not you possibly you know you look kind of the area of Africa and the population density of modern hunter gatherers you know these archaic homo sapiens could have numbered in the hundreds of thousands possibly half a million or even conceivably a million individuals and this would have been more than all other human species on earth.

[00:18:44]So they're very widespread. Uh they were abundant and they were also very longived. The Moroccan remains dating to 315,000 years ago are currently the oldest known homo sapiens. The skull and Apademma in Greece dates to 200,000 years ago. It's the oldest sapiens outside of Africa. They're around for a long time. They survived until relatively recently. We have these specimens from Grat Mandra in France dating to around 54,000 years ago. And we have specimens even younger than that, 20,000 years ago, 14,000 years ago in northwest Africa and Western Africa.

[00:19:20]So until very recently, uh, a 100,000 years ago, maybe even less than that, these were the dominant homo sapiens.

[00:19:30]And before then, it's difficult to find so much as a tooth or a jaw that does not have these archaic features, these big teeth and big brow ridges and low skulls. So almost everything we find up until remarkably recently most of what we find of homo sapiens is not our lineage the modern homo sapiens it is these archaic homo sapiens.

[00:19:52]So all this raises a lot of questions uh where do these primitive homo sapiens fit into our evolution? Did they give rise to us? Are these the ancestral populations we descend from or are they a side branch or multiple side branches of the human evolutionary tree?

[00:20:08]And how modern, how human, for lack of a better word, were they in terms of their behavior and and their thought processes, their minds? And lastly, where did they go? Did they evolve into or perhaps become absorbed into modern populations? Or do they simply go extinct? And if they did go extinct, why?

[00:20:28]And why are modern humans still here?

[00:20:32]So, it's tempting to see archaic sapiens as our direct ancestors because it would solve this huge problem. Where do we come from? We want to know where we come from. I mean, it's like, you know, the we want to know our origin story. The Bible starts out the very first chapter.

[00:20:47]Where do humans come from? Here's where we come from. And that's a nice story, but like, you know, if we want the scientific account, we want to find the ancestors of modern humans. We've been seeking this for hundreds of years, ever since Darwin, you know, laid out the ev, you know, these ideas that, you know, we evolved from, you know, we evolved from other species. Okay. Well, where are the fossils? Where are ancestors?

[00:21:09]And if you do interpret these archaic homo sapiens as ancestral, it would solve that problem. One of the greatest problems in science. Uh, which is precisely why you should be skeptical.

[00:21:18]Uh, it's kind of too good to be true.

[00:21:20]Science rarely gives you these nice answers. It gives you the data you want, especially in paleontology.

[00:21:26]Uh so in this scenario where they're ancestral to us, this odd mixture of primitive and modern features, these sapiens features, these more Neandertholic features, the reason they have this mix of features is because they're transitional forms. They're they're missing links between Neanderthalike hominins and fully modern humans. And again, this is a simple obvious explanation, but as so often happens in science, the simple obvious explanation seems to be wrong.

[00:21:55]Why is it wrong? Because archaic sapiens just appear too late in the fossil record. If they're ancestral, they should appear before the first modern humans. And they're the by the time we start seeing them, uh it's quite likely that modern humans had already evolved.

[00:22:14]So we can use molecular clocks and molecular clocks look at the genetic distance difference between two populations genetic distance and says okay assuming a certain a certain rate of evolution that you know so many mutations occur per generation how many generations how many years would it take to get this uh level of divergence between these two populations and you know we can look at you know the the deepest diverging population in the homo sapiens tree with the bushman versus more shallowing diverging populations like the pygmies, West Africans, East Africans, out of Africa people, etc., and say, okay, the deepest split in the evolutionary tree of modern homo sapiens to account for this genetic distance between all these far-flung descent lineages would require based on these models 300,000 years of evolution. So, the Bushman split off from everybody else about 300,000 years ago.

[00:23:07]And the implication is that something like us was already around 300,000 years ago. And again, this is purely in for the genetics. We do not have fossils to back up this scenario. Um there's a lot of missing data, what they would call ghost lineages, unre lineages unrecorded in the fossil tree. But the implication is that there's something 300,000 years ago uh when the Bushman split off from everybody else and the pygmy split off maybe 100,000 years after that. And the population that gave rise to all these modern people would have had modern features, fully modern features. The big domed heads and reduced brow ridges and prominent chins and short faces and and thin skull bones. That's another one I forgot to mention. Archaic Homo sapiens have really thick skull bones.

[00:23:51]So we have modern humans probably originating around 300,000 years ago.

[00:23:57]And then Scholola and Kafasa are appearing the fossil record 200,000 years after that.

[00:24:04]So if the molecular clock is correct and molecular clocks are kind of a dark art, but I think there's something to this and I think it's even approximately correct and there's there's a big error bar in that. You know, the actual data is something like 300,000 plus or minus 50,000. But either way, the the timing just doesn't work is we were appear we were already around by the time that we're finding these humans in, you know, Scholola and Kafa. So rather than representing an ancestral population, they're probably a primitive side branch of evolutionary tree, not on the main lineage leading up to us, but the side branch splitting off long before we emerged. And this is a side branch that went extinct, leaving no descendants.

[00:24:52]So what I'm going to argue is that all modern humans share these anatomical features we talked about except in Papa New Guinea and Australia where you have really high levels of Dennisovven DNA and you get you reacquire some of these archaic features like the brow ridges.

[00:25:09]But for the most part modern humans are characterized by reduced brow ridges, this very tall dome skull, very thin skull bones, short jaws, small face, very prominent chin.

[00:25:20]Now, is it impossible that each of these lineages independently evolved this morphology? You know, the out of Africa people evolved it and then, you know, like the pygmies evolved it and the Bushman evolved it and they and it's not impossible, but it seems unlikely that all evolved this exact same combination the exact same way. Uh so again, it's not impossible. But the simplest explanation that fits the facts is a single acquisition of this modern anatomy, the big dome skulls, these brow ridges, 300,000 years that is then retained until the present day by these descendant lineages. So the implication is if the molecular clock is right and the ancestor of living humans existed 300,000 years ago and we can then reconstruct what that ancestor looked like and it would have looked fully modern that excludes people like Skull and Kasa and Jebel Ehood and Yasi from being ancestral. They're too late.

[00:26:14]They're side branches. And the implication is that somewhere in Africa there are fully modern humans with these reduced brow ridges and we just haven't found them yet.

[00:26:28]So where exactly do the other sapiens fit into this picture? Where do archaic homo sapiens fit into the evolutionary tree?

[00:26:38]Are they an extinct subspecies or you know maybe even raise them to a full species that's distinct from us? I think the picture is a little more complicated. So remember all these primitive characteristics we're talking about the long skull, the big jaws, the thick cranial bones. The thing is these features vary even within archaic homo sapiens.

[00:27:00]So within the archaic some of these like Jebel Hood and Floresbad look really really primitive.

[00:27:08]They're archaic archaics and others like Shkull and Casa are far more advanced. They're quite modern archaics. So they they span a range from very very archaic archaics to more modern archaics and kind of stuff in between. I think well what does that imply?

[00:27:26]I think what we're seeing is actually a series of subspecies. Not one archaic subspecies, a whole bunch of archaic subspecies. And some of these split off a long time ago, maybe you know 500,000 700,000 years ago and others far more recently and they kind of as they split off from the lineage leading to us, they migrate to different parts of Africa and become specialized on these environments. So I think what we're seeing is lots of different archaic side branches leading up the main line towards fully modern homo sapiens. And within these lineages, there may even have been waves of replacement. So we may have highly archaic archaics being replaced by more modern archaics. So for example, the people of Morocco, these late archaics rather than descending from Jebel earhood might be a replacement wave. Uh so you know there might be some really complicated patterns in here and I think we're really just starting to understand these people. But we still don't even have that many fossils and a lot of it's pretty fragmentaryary and I think you know there's probably a lot more we're going to learn in the next you know 10 20 years I would suspect all this raises a question I if I in this scenario I'm painting here I'm saying okay these guys don't lead to us there are side branches and there's you know there's another lineage leading to us and you've probably noticed something about this which is that there's no fossil supporting this scenario. Uh there's this huge if if I'm saying that something fully modern existed 300,000 years ago, where are the fossils? And that that's a very good question. Um there is a remarkable posity of fossils of fully modern homo sapiens until remarkably recent.

[00:29:21]Um, some of the oldest fossils of fully modern homo sapiens are from Mumba rock shelter in Tanzania.

[00:29:30]And I think they they were formerly dated to around 100,000 years ago. And I think the current some recent work suggests they they're only 60,000 years old. So the oldest evidence of fully modern homo sapiens in Tanzania and East Africa is just 60,000 years ago. We actually have evidence that, you know, pe modern homo sapiens arrived in Australia before then. So is it possible that people in Australia before they were in the bush of Tanzania? Uh remarkable. Uh but maybe um in Classy's River in South Africa around 100,000 years ago, we have a number of fragmentaryary skull bones, but they appear to be fully modern uh with globular skulls and reduced brow ridges.

[00:30:08]At Border Cave, a little younger, maybe around 75,000 years ago, 75,000 to 100,000 years ago, we have a a highly modern skull and jaws. So that still leaves about, you know, a 200,000year gap there where there should be fossils of modern humans and we're just not seeing them.

[00:30:26]So how is it possible that we just have so little record of modern humans and until very recently the record in Africa and elsewhere is dominated by archaic homo sapiens?

[00:30:38]I think the answer is that we were not kind of the main story of human evolution for even for homo sapiens for a very long time.

[00:30:47]uh we were not the main characters. Uh we were a small side branch and we were not very numerous.

[00:30:55]And you know if if alien exobiologists came down and looked around and studied our planet and they looked at all the diversity of hominins, they'd see Neanderthalss and Dennis Owens and Homo sapiens, they might say, "Hey, homo sapiens, they're pretty successful.

[00:31:08]They're all over Africa and they're in the Middle East and into Europe." But they might not have picked our sublineage because you know fully modern homo sapiens because we were just one small subbranch of homo sapiens and not a very successful one. We were not very numerous. Uh and it's possible to look at modern human diversity and try to reconstruct our past. And what we can find is that models evolution suggests that human genetic diversity was quite low until relatively recently. What does that mean that low genetic diversity?

[00:31:41]What it implies is an extended genetic bottleneck.

[00:31:45]Um what's a genetic bottleneck? Well, think of like how island populations, you know, a handful of people colonize an island. You know, everybody's kind of related to everybody else. They're a little bit inbred and there's not a lot of genetic diversity there because everybody descends from a handful of colonists. Everyone's related to each other. And that's kind of how we were for a long time. Not quite as extreme as, you know, 50 people colonizing island. But they've estimated based on these reconstructions of of early human genetic diversity, the total population of humans on Earth was something like 25,000 or 30,000 people on the whole planet at least of fully modern homo sapiens. Our lineage existed at you know basically the size of a you know a small city or a large town uh for hundreds of thousands of years.

[00:32:28]So until relatively recently we start to expand out of our ancestral homeland and our numbers go up. uh there's just not many of us. We're not inhabiting a large area. We're hard to find. It's the archaic who dominated. They may have been 10 or 20 times more numerous than us. And so that's what we're tending to find in the fossil record because we just weren't that successful until relatively recently.

[00:32:52]Now, I know this probably sounds like special pleading. Um it's kind of like, you know, people talk about ancient, you know, ancient ice age civilizations.

[00:33:02]Well, where's all the evidence? Oh, it's under the sea, you know, the sea levels rose and covered up those ice age civilizations. Where is the evidence for Atlantis? Well, under the sea, obviously. Um, so I appreciate that that it it's kind of like this scenario involves invoking something we don't have any fossil evidence for, but we do have genetic evidence for it. And I would also argue that our skulls are so distinctive that strongly implies a long period of isolation where we're evolving in divergent from the rest of the homo sapiens. Uh that morphology is not something evolves in a thousand or 2,000 or 10,000 years. Uh our really highly specialized skulls took a while to evolve. So when that anatomy just kind of pops up out of nowhere, that tells you there's a lot of the fossil record that's just missing.

[00:33:49]What I would also say is that you know well again Africa is a huge place and it's not really that well explored in a lot of ways like we know a lot more about Neanderthalss because well where are all the universities? Where are all the museums? Where are all the archaeologists? There's a lot of them in Europe. Uh because that's where paleontology and paleo anthropology started. That's where people started building museums. Uh that's where you have all the archaeologists. That's you have a lot of the universities. That's have a lot of the funding. So, you know, people are constantly going out and digging up Neanderthal caves all the time. There are a lot of places in Africa that have just never been dug up because there just isn't there aren't enough archaeologists and there's not enough funding out there. So, so there's there's huge black holes in Africa. And these gaps are easily large enough to fit a huge homeland where modern sap homo sapiens could be hanging out for hundreds of thousands of years in isolation, relatively small population, few tens of thousands of people. And it's also especially the this area where we have this huge gap uh in the fossil record is where we have very high genetic diversity. So you have high genetic diversity in people like the Bushmen and the pygmies. And these are the two deepest branches of the human family tree. You know, the Bushmen split off from everybody else first. They kind of head south into the the Kalahari.

[00:35:06]Then the pygmies split off and then West Africans, East Africans, out of Africa people. So the fact that the two most ancient divergences in the family tree are occurring somewhere in southern Africa because we have these ancient lineages in southern Africa and this is an area where we just don't have many fossils.

[00:35:23]I think this is where the ancestral homo sapiens homeland is located. And if you think about it, something like, you know, I think, you know, 75 people per square mile, uh, one person needs like 1.3 square miles to to live off of hunting and foraging.

[00:35:40]So you could fit a population of 30,000 in something like 40,000 square miles roughly the area of Iowa or or England.

[00:35:49]Uh which sounds like a fairly large area but then consider that like you know Batswana is like five times that size.

[00:35:55]Zambia is seven times that size and South Africa is 10 times that size.

[00:35:58]These are huge countries. Uh so you could fit you know the a whole population of modern homo sapiens is one corner of these countries. Again Africa is really big. Uh that's probably another talk however but we were initially one of many competing lineages in Africa and not that numerous and not that widespread where this small isolated lineage is in one little pocket of Africa.

[00:36:26]So why did that change?

[00:36:30]If we were this kind of like side branch, this side story, not the main characters, why is it that they're extinct and we're still here?

[00:36:41]What happened to them?

[00:36:45]The answer, well, what happened to them?

[00:36:47]We did. I think modern homo sapiens are responsible for the extinction of archaic homo sapiens.

[00:36:58]So modern humans seem to start spreading out of their ancestral homeland around 300,000 years ago. This is when the Bushman split off and then the pygmies split off maybe 100,000 years after that. Then the West Africans, East Africans and then people move out of Africa and slowly people start migrating through Africa.

[00:37:17]And as we spread the other homo sapiens start going extinct. They disappear from South Africa as the ancestors of the Bushmen move south.

[00:37:25]They disappear from East Africa as the ancestors of the Sandawi, the Hodzabay, and other East African tribes move in.

[00:37:34]And curiously, um, archaic Homo sapiens in the Middle East, however, there's a different story. The Scholen Kafasa people disappear from the Middle East around 60,000 years ago as Neanderthalss move in and replace them.

[00:37:49]And this is something really remarkable and I think tells us something about these species because one thing you'll notice is that Neanderthalss were never able to displace modern homo sapiens. Like once the the the out of Africa peoples when they migrate out of Africa, they're able to hold ground and eventually expand and take out the Neanderthalss. And the Neanderthalss are never able to successfully push back against them. We had some advantage against Neanderthalss that they just they were just powerless to resist us. And yet Neanderthalss were able to outmatch archaic homo sapiens in the Levent in Israel at Scholen Cavsa.

[00:38:28]Another interesting detail is that we've recognized that Neanderthalss contain a small amount of Homo sapiens DNA. How did they get it? And this seems to be the result of an ancient interbreeding event uh something around 250,000 years ago. So Neanderthalss interbred with homo sapiens and acquired small amounts of homo sapiens DNA from an unknown population.

[00:38:51]And this is long before the out of Africa migration that leads to Europeans, Asians, American Indians, and Australians.

[00:38:59]So where could they get Homo sapiens DNA from? Well, they didn't get from modern homo sapiens. They get it from archaic homo sapiens. And something like 6% of Neanderthal DNA is actually archaic homo sapiens. They are hybrids.

[00:39:15]This leaves us with uh uh leaves us with a few remaining archaic populations.

[00:39:20]However, there are still archaic remaining in North Africa. And the North Africans are one of the last populations to go. Uh modern humans will move up the Nile around 30,000 years ago from East Africa into into Egypt and they'll replace the archaic sapiens found there. They will then slowly make their way across North Africa into northwest Africa.

[00:39:44]And today still out in Morocco, you can just walk around in the desert and find these these spear points, these points made by our crayom sapiens. And and here here's one I found when I was wandering around in the desert. We were out looking for, you know, dinosaur sightes of, you know, carcardonosaurus and and spinosaurus and things like that. And just out on the flats, there's pickup chipped rocks and there's an Tyrion point there. And this one's pretty, it doesn't look like much, but that's cuz the tip is broken off.

[00:40:12]But that actually kind of makes it cooler because, you know, this you can tell the spear point was used is they threw it at an animal or maybe a person, hit bone or broke or maybe it missed and hit a rock. But this spear point has a story behind it. And this is a trace of archaic homo sapiens. These things are they're found everywhere out in the desert in Morocco and lots of lots of chipped rocks. Probably a lot of those left by these archaic homo sapiens as well. And again, these are these are tanged level wall points. They would take a level wall point and then chip the base to create this this kind of you know little stem or tang that used to haft it onto a spear. And archaic homo sapiens the only people who made these points. So they're a very good indicator of archaic homo sapiens. and they're widespread in North Africa and they vanished from Morocco and Western Sahara around 20,000 years ago.

[00:41:02]So archaic homo sapiens hang on for a really long time in northwest Africa.

[00:41:09]They're hanging on in Northwest Africa after modern humans have arrived in Australia 65,000 years ago after humans conquered Europe and Asia 40,000 years ago after humans traveled across the bearing land bridge to the Americas 30,000 years ago. Uh, these are some of the last archaic humans on the planet, archaic homo sapiens.

[00:41:28]And the first American Indians existed long before the last archaic homo sapiens went extinct in Africa, which is crazy to think about. And the Sahara is a vast place.

[00:41:39]And there's a lot of places out there just never been well studied. I don't think there's really been nearly enough archaeological work in North Africa recently. So, is it possible that archaic humans hung on there until even more recently? Well, it's it's not impossible. Like I think we know a lot about Europe. Again, lots of archaeologists, lots of museums. We know when the anthals went extinct. We know a lot less about Northwest Africa. And really be I think it'd be wonderful to see more work done out there.

[00:42:09]There's one known population that may be even younger than the Northwest African populations.

[00:42:16]The last archaic homo sapiens population that we know of is from a place called Iwa Oro Cave in Nigeria.

[00:42:22]and they date to as recently as 14,000 years ago. Um, given how poorly studied much of Africa is, these people almost certainly survived after that point, but we don't know how long. Was it, you know, a 100 years, 500,000, 500 years, you know, a thousand years, thousands of years? We just don't know.

[00:42:42]And I'm speculating obviously, but it wouldn't surprise me if we had archaic homo sapiens hanging on in Africa until the introduction of hering and farming.

[00:42:54]Uh possibly even into historic times in some remote valley. And I I know this sounds kind of crazy, but there's been a lot of just that, you know, a lot of the replacement of of hunter gatherers in Africa has happened surprisingly recently. Um you know the Messiah moved down into the Serengeti and replaced the hunter gatherers there and you know like in in the Renaissance times for example.

[00:43:15]Um Herodotus around 500 BC talks about a population that appear to be hunter gatherers. He calls them trogodite Ethiopians which means caved dwelling Ethiopians that live out in the desert.

[00:43:28]And the description of these people corresponds to some type of huntergatherer tribe living in North Africa you know in you know 450 BC and we don't know anything about them that his record is the only record we have of these people but there were hunter gatherers surviving this area into historic times that have since these tribes have since gone extinct. So could there be you know when did the archaic go out in Africa? We we just don't know.

[00:43:57]Um, and you know, we we just need more data to know, but it would be, you know, again, a lot of a lot of hunter gatherers have gone extinct surprisingly recently, and it's not inconceivable that, you know, in some parts of Africa, maybe our cake populations survived until surprisingly recently. There's just, again, Africa is really big. There's a lot we don't know about it, and there's a lot more research we need to do out there.

[00:44:21]So the question becomes um our expansion out of southern Africa sees them replaced in Africa and go extinct and in the same way that our expansion also wipes out Neanderthalss and Dennisovvens and Homoactus and the question becomes why did we survive and they didn't? I mean, we're both homo sapiens, right? So, what did we have that they didn't? And this is obviously a difficult problem because a lot of explanations involve things like, well, we our imagination, our ability to reason, language, social structures, none of which directly preserve. These things may however leave indirect traces in tools, in the burial of dead or or even in the bones. uh culture can exert a strong you know you know we can see in the bones what per potentially what people are selecting on what behavioral traits are being selected on and I think the answer may lie in something very very obvious kind of like right in front of our faces well like literally our faces uh I think the answer to why we made it and they didn't is in those skulls it's written in their bones and it's written in our bones as well and I think these traits that modern humans have small brow ridges, bubble shaped, crania, reduced jaws, thin cranial bones are telling us something. And these have critical implications. Not so much functional like, okay, here's how we chew our food as developmental, telling us about human developmental patterns.

[00:45:50]And the shape of the skull is telling us about selection for behaviors in the brain.

[00:45:58]So, think about it. What are the features that distinguish modern homo sapiens that make us different from other species? Um, in fact, these features that we think of as unique to homo sapiens are not unique to homo sapiens.

[00:46:14]What I've just spent a whole long time whole lecture telling you why these features are important unique. They are homo sapiens is unique in having these features in the adult. The features that make us look so weird compared to skull and cafsa and neanderthalss and homoractus are actually seen in juveniles of Neanderthalss and homoctus and and pro you know skull and casa as well. Uh and juvenile hominins have small brow ridges and very domed rounded heads and relatively short faces. So the features we think of as unique to us, we are unique in having them as adults, but they show up in the juveniles of other hominins.

[00:46:58]And we can go further. These features that we think of as as making humans human uh are even found in juvenile apes like young chimpanzees.

[00:47:08]So compared to other hominins and compared to other apes, we are literally babyfaced. We look like juveniles of Neanderthalss. We look like juvenile chimpanzees. We have very immature skull shapes even though even as adults.

[00:47:24]Now this is really curious because this pattern of juvenilization, what is this telling us? Well, what's really interesting is it mirrors what we see in domestic animals compared to wolves. Domestic dogs have relatively shorter faces and higher foreheads.

[00:47:42]Domestic dogs look a bit like wolf puppies because these are features that you see in wolf pups as they have more strongly domed heads and shorter faces.

[00:47:51]Why is this happening? Well, the theory is that in in the domestication of dogs, we are selecting for dogs that behave like puppies. They're more playful.

[00:48:00]They're less aggressive. They're less likely to try and bite you and try and kill you. They're more likely to approach a human and less likely to attack them. So what happens is we have these dogs, you know, these bulls, and we're trying to domesticate them, use them for hunting and for guard purposes and just companionship. And we keep the ones that are the best dogs and the best dogs are more puppy-like. They're more friendly. They're more agreeable.

[00:48:19]They're not going to try and attack you.

[00:48:21]So we select for puppy-like behaviors, we end up with like dogs that look like puppies. But because we're selecting for animals that are have immature behaviors, we're ending up with animals that their physical development patterns never quite finish. We're getting immature looking skulls because we're looking for immature behaviors. And this is not just a dog thing either. This is like we see this in basically it's a universal pattern in domestic animals.

[00:48:49]So if you look at juveniles of almost any mammal, uh they have more domed heads, they have shorter faces, they have thinner skull bones. That's another one that dogs shows. They have thinning skull bones uh just like homo sapiens do compared to archaic homo sapiens.

[00:49:04]So when we domesticated animals, they end up being juvenileized. This is a general pattern of domestication of animals. We are selecting for animals that are less aggressive and more open to, you know, forming social bonds. They have a longer period of being willing to bond with other animals and less, you know, likely to attack them. So we're selecting for juvenile characters and that is selecting for juvenileization of the entire animal, including the skull.

[00:49:31]So again, we're getting these juvenileized features of the animals in the adult because we're selecting for juvenile behaviors.

[00:49:41]So you look at, you know, domestic cats kind of look like kittens of wild cats and domestic pigs kind of look like piglets of boores and and domestic sheep kind of look like, you know, they look like lambs of wild wild sheep and so on and so forth. We have this pattern where when we domesticate and select for low aggression and agreeability, we get these juvenile skulls in with thin bones in all these various domestic animals. Again, it's it's an, you know, it's it's a striking pattern that we see across mammals over and over and over again. So, is something like that happening to us? Are we being effectively domesticated? And well, I mean, who's domesticating us? is like aliens up there and they're saying we want to breed less aggressive humans.

[00:50:29]No, we're domesticating each other. Uh, you know, through probably a variety of different processes. You maybe one guy's too aggressive. He's kind of being an You just stick a spear in him and get rid of him. You remove the population. You do that enough times and you end up with low aggression individuals. Maybe they look more juvenile. Uh, probably a big part selection. you know, if women are choosing guys who are, you know, less violent, uh, you know, they maybe end up with more juvenile features. And then just kind of who who succeeds in society, you know, a society that that thrives on cooperation rather than aggression is going to the people who rise at the top of that society and are being, you know, high status and able to get mates and have successful kids and things like that are going to be the ones that are slightly less aggressive.

[00:51:11]And that might so all these various processes might be going on in some combination. But the end result is the more aggressive individuals are being selected out of the population. More cooperative, playful, open social individuals are being selected for. And what you end up with is juvenileized skulls. We have these babyfaced skulls.

[00:51:31]So in the same way that dogs and cats are being bred to get along with humans, they end up looking like puppies and kitt kittens. Humans are being bred to get along with other humans. We ended up looking like children and that explains our weird skulls. So, I've just explained to you why our skulls are different, but what does that tell us about look why we managed to win and they didn't?

[00:51:56]So, I think what's going on here is we are selecting for a species that is much more social. Selection for juvenile behaviors, low aggression, openness to novelty and new people is allowing us to be more social.

[00:52:11]and to form more friends, larger social groups, larger bands, bigger tribes, alliances between tribes, all these things. And this produces our immature-looking skulls as a side effect.

[00:52:23]So, we're becoming more social and more cooperative and less aggressive.

[00:52:28]Would this also make us more peaceful?

[00:52:31]Well, that's where it gets really complicated because paradoxically, it may in fact have been this high sociability and low aggression that made modern humans so incredibly dangerous to primitive homo sapiens, to Neanderthalss, Denisovvens, Homoctus, and so on and so forth. And that seems kind of ironic or paradoxical. How is it that being more social, less aggressive would make you more dangerous?

[00:52:59]And the reason why is because the one place that cooperation is going to be most important is in warfare. The ability to form large groups gives you military superiority.

[00:53:11]Think about it. You know, back in prehistoric times, you know, it wasn't like World War II where technology is evolving rapidly and you've got, you know, you've got the nuclear bomb and he doesn't you win because of better technology. Uh, everybody had the same technology. Everybody had, you know, spears, they had axes, they had, you know, clubs and throwing clubs and, you know, wasn't, you know, basically. So, how do you get an edge when basically everyone has the same technology? You have technological parody against your opponents. The way you get an edge against your opponents is you bring more fighters to the field. You have larger groups and that is the way you get a military advantage. You want a bigger band. Instead of having a band of 50, you want a band of 60 or 100.

[00:53:55]You want to ally your bands into a tribe.

[00:53:59]20 bands of 50 will form a tribe of a thousand.

[00:54:03]You might form alliances between tribes.

[00:54:07]And even even very uh very conservative hunter gatherer societies, people like the Hodsbay and Bushman are able to form alliances between tribes. It's military alliances.

[00:54:18]So we think of, you know, throughout warfare, one of the consistent patterns we see in warfare, one of the most important patterns is alliances. You know, when the Greeks are trying to fight off the Persians, they all these various cities that don't really get along, like the Spartans, Athenians, they ally together. And when the Romans were fighting the Carthaginians, they're not doing it alone. They have all these they have these uh various citystates and tribes they're allied with that provide them with soldiers. And the Carthaginians likewise have their allies. sort of seeing alliance fighting alliances back in the Punic Wars. And of course, World War II, you have not just one country versus another. You have two great military alliances, the greatest military alliances of all time, the Axis powers and the Allies.

[00:54:58]It's right there in the name, the Allies. And the the the alliance that won was the bigger alliance. So forming alliance is a fundamental feature of human warfare, but it's not just found in civilizations and states. It's also found in tribes. and tribes will get together with other tribes and say, "We hate this other tribe. Let's go get them." So, we have this ability to form these very, very large social groups.

[00:55:22]And in warfare is when that ability is most important. Uh being able to cooperate is the difference between being defeated on the battlefield and potentially being wiped out or wiping the other guy out.

[00:55:35]So, it's this innate sociability, our ability to be friendly, our ability to, you know, dial down our aggressive impulses that allows us to form these larger social groups. Now, this might seem a bit speculative that, well, how do we know that homo sapiens had bigger social groups than others? We can actually get at this because uh this again, this leaves an imprint on our on our DNA quite literally. And what we can see is that Neanderthalss show relatively low genetic diversity compared to homo sapiens because we can get Neanderthal DNA from ancient bones.

[00:56:08]And the implication is their low genetic diversity. They're they're more inbred is because they lived in smaller groups.

[00:56:15]Ancient humans have higher genetic diversity uh suggesting these rare mutations are not being lost through these bottleneck effects. They're in larger populations. They're less inbred.

[00:56:24]We seem to have formed larger social groups than Neanderthalss.

[00:56:28]And this is probably why we had an advantage against Neanderthalss. And I suspect something similar is going on with the archaic homo sapiens, although unfortunately do not yet have any DNA from them. But maybe someday we will and we'll be able to test this hypothesis.

[00:56:43]And the testable prediction is that archaic homo sapiens will have lower genetic diversity uh because they live in lower social smaller social groups.

[00:56:52]So what does this mean? it. Our ability to socialize, to get along with each other, to make friends, to make allies uh and alliances is what allowed us to to basically defeat the other homo other homo sapiens out there. It's it's all about, you know, it's about friendship.

[00:57:11]Uh I know this sounds like the moral of a children's cartoon, uh but it's kind of true. Friendship is our superpower.

[00:57:21]And I know this might seem really counterintuitive. Well, I mean, we won because we were less aggressive. But the thing is, if we're less instinctively hostile, less prone to aggressive outbursts, better able to make friends and peace, that doesn't mean we're pushovers. It meant we were kind of more coldblooded. We could hold off on violence until we were ready. And we get that big alliance together and that group swing swing, you know, kind of swept in through the valley and wipes out our rivals. We weren't instinctively aggressive, like we were kind of very cold and cunning and calculating.

[00:57:54]We were more business-like, if you will, and our business was waging war against these other tribes. You know, think of chimps and they're hooting and panting, and then think of a bunch of generals in the Pentagon calmly plotting to wipe out another military with their stealth bombers.

[00:58:10]Now, humans do have this capacity to descend into a frenzy of violence. But you also have this capability of killing in a very calm, calculating, rational fashion.

[00:58:21]Look at this picture. You know, this is in the Pentagon. All these are all the top brass in the military in the Pentagon.

[00:58:28]Look how friendly everyone looks here.

[00:58:31]And when you think about it, that's kind of terrifying. Uh this is not this is not if you know if you're fighting these guys this is not a this is a kind of scary picture to look at. Uh there's that great line by by Mattis. He says be polite, be professional, and have a plan to kill everyone you meet. And that is how homo sapiens wages war.

[00:58:55]And the smile of homo sapiens masks how deadly we are. And that ability to get along, that friendliness that the smile shows is part of why we're so dangerous.

[00:59:04]And that mentality, that ability to kill rationally rather than emotionally, to suppress our emotions and work together with people, even people who might not want to. Uh that is what made humans so incredibly dangerous, I would argue.

[00:59:19]So what's it all mean? In recent years, it's become clear that we shared the planet with all these other human species. Neanderthalss, denisovans, homoctus, homoesensis, homophoresensis, homolusonensis, homo eloliti and likely others we have yet to find. There all these other species and as we expand out of southern Africa and throughout Eurasia, they go extinct.

[00:59:44]There is this major mass extinction of other human species and we drove it. We are the sole survivors. Homo sapiens is the sole surviving species of many human species.

[00:59:55]What I don't think we fully appreciate yet is that the same pattern occurs within homo sapiens. In the same way that we wipe out all these other human species, we wipe out the other homo sapiens.

[01:00:11]Homo sapiens was far more diverse in the past.

[01:00:15]There were many different competing lineages. They shared primitive anatomical features in Neanderthalss.

[01:00:21]They existed in different parts of the world and our lineage was just one of many. There were a few tens of thousands of people living somewhere in the bush of southern Africa.

[01:00:32]We were so obscure 300,000 years ago that we haven't even found any fossils from this ancestral population. Just some, you know, some anonymous part of the African bush is our homeland and no one's dug for fossils there. So, we just haven't found our ancestors.

[01:00:49]And yet out of this, you know, kind of humble beginning, uh, you like the hero in a fairy tale, out of this humble beginning, we kind of went out and we took over the world and in the process, we wiped out all these other homo sapiens.

[01:01:04]Modern humans are the only living survivors of our species. Why is that?

[01:01:10]Because when we expanded, we took their land or we drove them off or we killed them. We are the only surviving homo sapiens because we killed the other homo sapiens.

[01:01:21]We weren't really unique in this, however. I mean, maybe it looks, wow, we're so much worse than all these other lineages. And the reality is probably no, we weren't. Um, we see, for example, around 65,000 years ago, one group of Neanderthals starts to expand in Europe. And as this group expands out, they start wiping out all the other Neanderthalss.

[01:01:43]uh maybe this group that wipes out the Scholenasa people in the Middle East.

[01:01:47]But there is a Neanderthal expansion that leads to the extinction of other Neandthal lineages. It appears and that's at least consistent. There are a lot of different ways you could read this, but it's consistent with the idea that Neanderthalss saw expansions of one people wiping out other members of their species.

[01:02:03]I think it's highly likely that archaic homo sapiens wiped out other archaic homo sapiens. uh later archaics in North Africa for example thean people may have been part of the same wave that gave rise to the stolen kafsa people and they may have wiped out the more primitive Jebel earhood archaic homo sapiens. So it is quite possible there were waves of replacement within homo sapiens with one archaic lineage replacing another archaic lineage until finally we came along. And again this is something where we're trying to you know reconstruct a great deal about human evolution from very limited remains. But you know we just have to go out there and dig up more fossils and see what's going on.

[01:02:41]But I strongly suspect this pattern of replacement is going to be found to be widespread not just in modern homo sapiens but in Neanderthalss and archaic homo sapiens.

[01:02:54]The emergence of our species, the emergence of our lineage of modern homo sapiens was a process of both creation and destruction and an incredible diversity of archaic humans evolved. Different species like the anderthalss and dennisovvens and homo erectus and homoesensis with their own unique adaptations and maybe different ways of looking at the world and different behaviors. They may have been human in very different ways than we are.

[01:03:22]And we also saw the appearance of archaic subspecies of homo sapiens. And evolution created these this incredible diversity.

[01:03:31]And then they are wiped out by competition between lineages.

[01:03:36]So evolution is therefore an additive process like sculpting with clay where you add clay upon clay and a subtractive process like sculpting with marble.

[01:03:49]These archaic species and archaic homo sapiens were carved away and carved away until only we remained.

[01:03:58]Like Michelangelo sculpting a block of rock and carving away everything that doesn't look like a man.

[01:04:08]And we continue this pattern within modern homo sapiens. There are lineages of humans, tribes or races. I don't know what you want to call them, but there are major languages of homo sapiens that are no longer in existence.

[01:04:21]There is a group called the ghost modern Africans that we know from their DNA, but we don't have their bones or tools as far as we know. Uh there are ancient North Africans. There are people represented by remains at like Aasi ones, Laticon, and Bachokiro in Eastern Europe that seem to represent extinct modern lineages that are not related to modern Europeans. They're in Europe.

[01:04:42]They're modern homo sapiens in Europe, but they're not related to Europeans like chromagnons or or Neolithic farmers. They're archaic lineages of of modern homo sapiens. They're no longer here. So, having wiped out the archaic and having wiped out Neanderthalss, we start wiping out each other.

[01:05:03]It may however be that these archaic people survive at some level uh in a way through the DNA passed down to us.

[01:05:10]So maybe 6% of Neanderthal DNA is archaic sapiens and our DNA is about 1 to 2% Neanderthal. So if you do the math um that you know kind of 1 to 2% or 6% it's possible it's something on the order of 0.1% that is a tenth of 1% of DNA in non-African peoples people in Europe and Asia comes from these archaic homo sapiens by way of neanderthalss and you know one part in a thousand doesn't sound like a lot right but hey you know you've got a you've got a genome with three billion base pairs.

[01:05:48]The implication one in a thousand. That means three million of your base pairs may come from archaic homo sapiens via the Neanderthalss.

[01:05:58]And there might be interbreeding or events that we haven't recognized yet.

[01:06:02]Um we have yet to recognize intreeding events, hybridization, direct hybridization between archaic homo sapiens and modern homo sapiens. But that doesn't mean it didn't happen. it just might be really hard to recognize. We can recognize when Neanderthal DNA and Dennisovven DNA gets to homo sapiens because it's so weird.

[01:06:23]It's like, okay, where did this come from? Uh because they split off from us, you know, close to a million years ago, their their DNA is quite divergent. So when it mixes with ours, it's very obvious. But you take another homo sapiens and you mix it in with homo sapiens, it might not be obvious that that's coming from another lineage as opposed to, oh, you just might assume, well, that's part of the ancestral variation of our population.

[01:06:43]So, I think if we can get more DNA, if we can ever get DNA from these people, uh, or from, you know, archaic homo, you know, from archaic homo sapiens or from early homo sapiens in Africa somewhere, uh, it might tell us a lot. And I have a hunch um you know I'll bet you a beer uh I wouldn't bet my career or my life on it but like I'd bet you a beer that like I think we will find interbreeding events uh between modern homo sapiens archaic homo sapiens because there's a widespread pattern wherever we go we kind of tended to interbreed with the locals the Neanderthalss denovven and these guys are even more like us than they were so it seems unlikely that we would not have interbred with them ever so I think we will eventually find archaic homo sapiens but they're not entirely gone, that they are maybe still part of us.

[01:07:33]So what's it all mean? The humans that exist today are the result of hundreds of thousands of years of conflict.

[01:07:41]Other with conflict with other groups like Neanderthalss and archaic homo sapiens and these other groups also their history is one of conflict.

[01:07:50]Neanderthalss and archaic homo sapiens would expand out and wipe out their competitors. And all these various lineages, modern homo sapiens, archaic homo sapiens, Neanderthalss were engaged in conflict over territory, intertribal warfare, conflict replacement, migration, um, genocide, if you want to call it that, because in effect these these conflicts resulted in people being wiped off the face of the earth. And this took place over hundreds and thousands of years.

[01:08:19]And we emerged not because we were necessarily more violent the others but in fact maybe the opposite because we were more restrained in our violence, more cooperative and more social.

[01:08:30]Ironically, we were more cooperative and that made us more competitive.

[01:08:34]Cooperation is really hard to do. Uh think about it, you know, think about a group project in university and how hard it was to get, you know, get everybody to work together and not have people freeloading and you know, listing directions or agreeing on runs things.

[01:08:48]Cooperation is super hard. And we, however, became better at it than the other species.

[01:08:56]And we survived as a result of that, we survived hundreds of thousands of years of intertribal warfare, tribe fighting tribe because we were better at it.

[01:09:07]And our origins are tied up in the story of their disappearance and extinction.

[01:09:11]Um, our origins and their extinction are different parts of the same story.