The complex evolution of homo sapiens (that's you)

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The purpose of me posting this video, is to present an objective explanation of human evolution from the perspective of people who are involved with archeology, paleontology, and general science as well as people who just plain love history. Jehovah's Witnesses, like many other fundamentalist abd Bible literalist groups often characturize the process of evolution through bad faith arguments.

This wonderful video breaks down what is currently understood about the African origins of humankind and breaks it down Barney style. It discusses the challenges paleontologists go through to reconstruct the past acknowledges that we have a long way to go to get all the answers. But the verdict is in. It has been in for over 200 years. Like it or not. Evolution is real and humans are one of the best known examples of it.

👍︎︎ 12 👤︎︎ u/Americanshanty 📅︎︎ Sep 19 2021 🗫︎ replies

Man I love Stephan Milo, he does such a great job and such good research into this stuff. It’s so interesting to me learning about the history of our species and the different offshoots of the homo genus that used to exist as well as Australopithecus and Paranthropus genuses, and to me it’s really humbling to learn about it all and how it’s all managed to culminate in us, Homo sapiens. As well as the new adaptations in Homo sapiens that could’ve eventually led to speciation had certain populations remained isolated like the population living on an island in Oceania with enlarged spleens that are able to dive for 14 minutes on average or those with increased hemoglobin in their blood so they can survive higher altitudes. And even just the fact that a third of the population can drink milk into adulthood now, idk to me everything to deal with this is just fascinating

👍︎︎ 8 👤︎︎ u/spewinator 📅︎︎ Sep 19 2021 🗫︎ replies

Commenting to watch later

👍︎︎ 3 👤︎︎ u/DLWOIM 📅︎︎ Sep 19 2021 🗫︎ replies
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There are thousands of different cultures around  the world, each one with its own beautiful,   fascinating, unique expression of what it means to  be human. I truly mean that, wherever you're from,   wherever you're watching this there is something  really special about your culture. I I believe   that to my core. Every person, every nation,  absolutely everybody has their own story to   tell it's just it's just what makes history and  archaeology so endlessly interesting. Despite all   of our differences though there's one story which  is shared by absolutely everyone, our evolution.   Today I want to discuss what we know, but  more importantly what we don't know about   the evolution of you. We're going to take a look  at the last common ancestor of us and our closest   relatives neanderthals and denisovans. We're going  to discuss the evidence for our African evolution   before moving on to when we left that region  burst onto the world like a invasive species   and the contradictory evidence that really  runs right through the heart of our ideas.   It should be well good. It should  be well interesting, big thumbs up! Before I start the video, I do have to give a  massive thanks to boneclones.com for providing me   with this wide array of hominin skulls that you  see before you. I've been using boneclones.com   since august 24 2019 when I made a video on  paranthropus here. If you've seen any of my   videos on human evolution all the skulls have come  from boneclones.com. The reason I buy from them   is because these are exact replicas of specific  fossils that they (archaeologists) found.   These aren't just facsimiles ,these don't just  approximately look like a neanderthal. This is   an exact replica of a neanderthal skull, an exact  replica of a homo erectus skull, and i really   love that attention to detail. That's the  attention to detail I try to bring with   the information in my videos and so that's the  attention to detail I like in the props that I use   for these videos. If you're interested in human  evolution, I know you're probably interested in   what they sell. I would probably own paranthropus  even if i didn't make these videos because   it was learning about them that really sparked  my interest in human evolution and pre-history   and realistically it changed the course of my  life. I love having a visual memento of that.   I love being able to look paranthropus boise in  the face every day and and see my evolutionary   history in the flesh.... in the flesh? Not  in the flesh these aren't these aren't real But i love being able to to see that I just  truly love owning these things they're so   interesting to me and everyone who comes into my  house always asks about the skulls uh it's just   a cool as hell thing to own so if that tickles  your interest a little bit i suspect it might   head on over to boneclones.com There's a link  in the pinned comment. Link in the description.   Use promo code stefan for $20 off and  yeah big shout out to bone clones for   providing me these skulls to make  this video as cool as possible. Usually when we talk about a last common ancestor  we're talking about the very earliest hominins   before even the australopiths. The last common  ancestor of us and chimpanzees. However,   today as we're really hyper focusing on the  evolution of homo sapiens, you and me. We're   focusing on the last common ancestor of us and our  closest relatives, neanderthals and denisovans.   Who were they? When did they live? Where did they  live? These are all fantastic questions that to   put it frankly uh we don't have the answer to.  Homo erectus was probably the first hominin to   leave Africa at around 1.8 million years ago and  this left scattered populations of archaic humans   across Africa, Asia and Europe. Each  one going about their lives, evolving,   adapting to their particular climate, their  particular circumstances but also periodically   meeting, boinking, swapping genes, swapping  ideas. Trying to pinpoint our direct ancestor,   untangling them from this really complicated  web of relationships is naturally an extremely   difficult thing to do. Genetic studies  of five neanderthal remains from Belgium,   France, Croatia and Russia have shown that the  last common ancestor lived at least five hundred   and thirty thousand years ago. But that's just the  the minimum time. It could have been as long as   seven hundred thousand to eight hundred thousand,  maybe even 1 million years ago who knows. So we   have this roughly 300,000 year period, maybe even  longer, when they could have lived but exactly who   it was is not known. This time period is  known as the muddle in the middle because   before it we had homo erectus after it we  have neanderthals, homo sapiens, denisovans,   but between these two groups of archaic humans  it's just an absolute mess and we just have a very   difficult time understanding the relationships  between the fossils that we have found   and unfortunately as well we haven't actually  found that many fossils from this key time period.   So it's really hard to answer these big questions  when we're just dealing with a few specimens. One key puzzle in this whole debate has been  the site of sima de los huesos, the pit of   bones, fantastic name, in atapuerca, sort of  north-central Spain. 430,000 years ago this region   was home to a group of hominins who were living  a really classic paleolithic lifestyle. They were   almost certainly living in their family groups,  hunting large game like rhinos and horses with   primitive wooden spears, and perhaps deliberately  bringing their dead to this cave. There's not much   evidence of occupation at the sima, it doesn't  really look like anyone was living there. We also   don't see much evidence of carnivore activity  and yet 28 hominins were deposited there. It's   possible that these archaic humans, these ancient  hominins were deliberately bringing their dead   to this particular spot. Which raises so many  interesting questions about their intelligence   and their society and and how they lived together  and how they loved each other, maybe? It's really   absolutely a fascinating place. These remains  have been given the title homo heidelbergensis,   which is a a notoriously difficult hominin species  to define. Because we have this muddle in the   middle where we aren't sure of the relationships  between the hominins many fossils have been given   the title homo heidelbergensis but whether they  truly are all the same species and deserve to   be grouped together is a matter of huge debate.  Was this group of hominins our common ancestor   though? It seems not. Genetic tests revealed  that they were early or proto-neanderthals,   after the split between us and neanderthals and  firmly on their side of our family tree. To be   fair some anthropologists had predicted this based  on the similarities between neanderthal and the   skulls from atapuerca but it is always obviously  fantastic to get that genetic confirmation, and   to be able to really accurately place them on our  evolutionary tree. So as interesting as they are,   they are not a direct ancestor of homo sapiens  they were not the common ancestor of us and   neanderthals. Let's stay in atapuerca but go  further back in time to around 850,000 years ago.   In 1994 archaeologists discovered the remains of  several people, mainly children, who seemingly   had been the victims of cannibalism. What can i  say? Life was hard in the paleolithic. Sometimes   your ancestors probably had to eat children,  that's just the way it went back in the day. These   remains have been given the title homo antecessor,  or pioneer man, and the best preserved of them is   called the child of gran dolina. This child (girl)  was about 10 years old when they seemingly became   someone's lunch and the remains have attracted a  lot of attention because of the flatness of the   face. One of the key features that anthropologists  and archaeologists look for in a fossil to   determine whether it's a homo sapiens is this flat  face placed directly under the skull and, as you   can see this child of gran dolina, their face  is very flat compared to earlier hominins like   homo erectus and even later hominins like homo  heidelbergensis. It seems flatter like ours. So   was this child a direct ancestor of ours, a very  distant ancestor of ours? Well again it seems not. Getting dna out of a fossil that is 850,000 years  old is exceptionally difficult but new scientific   techniques analyze individual proteins which  survive better in the archaeological record.   Proteins on their own of course cannot  give us as much information as DNA,   so please bear in mind that this uh interpretation  of the results could change dramatically in the   future if we improve our technology. But  proteins can give us clues to ancestry   and it seems that homo antecessor was perhaps  a sister group of our last common ancestor.   Living around that same time, a very close  relative but not our direct ancestor,   not the common ancestor, not an early example of  the homo sapiens lineage. The child of gran dolina   really illustrates a difficult problem that  anthropologists have. Just because a specimen   might share many of the same physical features  as us, it does not mean that they're our direct   ancestor. Evolution spins a really complicated  web. So as it stands none of the remains from   atapuerca are on our homo sapiens lineage or are  the last common ancestor of us and neanderthals. This is basically the situation across the  entire world. Anthropologists have been able to   exclude some examples and determine who is not  our direct ancestor but finding that common   ancestor finding those really early homo sapiens  has eluded us, we still have not found them yet.   Considering what we're going to discuss later  about the origins of our species in Africa, it is   very likely that the common ancestor of us and  neanderthals lived there. But the past being   so complicated, we do have to keep an open mind  that the common ancestor of us neanderthals and   denisovans could have lived in Eurasia. After  all that is where our two closest relatives   lived and evolved so it's not unreasonable at all  to think that our common ancestor might have lived   somewhere in western Asia, maybe even in  south Asia, India. Our understanding of   this time period in India is not great.  We have a lot of tools but so far no   human remains from this very early time period  so we have to keep an open mind that they they   could have lived in India perhaps. So  anthropologists are keeping an open mind   uh but nevertheless Africa for sure  has a special place in our evolution Wherever our ancestors lived before 300,000  years ago, it's abundantly clear that since   that time Africa has been the beating heart of  our evolution. This is confirmed not only by   the fossil record but also overwhelmingly by our  genetics. There are key features of our anatomy   that anthropologists look for when trying to  determine whether a fossil is a homo sapiens   or not. As I mentioned earlier we have a small  flat face, this face should sit directly under   our brain case, we have a really distinctive chin,  and we have this really round skull. Globular is   the technical term, globby globby glob glob. Now  of course we have to bear in mind that there is a   lot of variation in how modern humans appear and  this variation extends deep into the paleolithic,   probably even more variation honestly. So  these aren't necessarily hard and fast rules   uh but these are these are the features that  could indicate that a fossil is a homo sapiens. The earliest fossils that we could describe as  potentially being a homo sapiens and archaic   form of homo sapiens come from Jebel Irhoud  in Morocco and date to around 300,000 years   ago. So far five individuals have been excavated  and as you can see they do have this small flat   face directly under the brain case but this skull  is not globular. It's it's egg-shaped, it's much   similar to a neanderthal much more similar to  homo heidelbergensis. Because of the shape of   this skull we can't consider them modern humans,  modern homo sapiens but they have enough features   that we could consider them perhaps archaic homo  sapiens. A very early ancestor of ours. Over on   the other side of Africa from Herto, Ethiopia, the  owner of this skull lived around 160,000 years ago   and as you can see is very round very globular but  has these absolutely chunking brow ridges. Really   thick, really pronounced and that's a very archaic  feature you could say in our in our species.   As you can see from these two examples, humans in  Africa during this middle paleolithic exhibit a   real mosaic of features. The evolution into  our modern form anatomically modern humans   seems to have been a really slow process that  has taken hundreds of thousands of years.   This mosaic of features continues for a long time  in the archaeological record. A skull from Omo in   Ethiopia is very round, very modern looking but  dates to 190,000 years old. Skulls from Qafzeh   in Israel day to around 120 to 90,000 years  old and again are quite modern. I know Israel   is not in Africa we're gonna get to that don't  worry. Yet a skull from Iwo Eleru in Nigeria   has a much more archaic form, like Jebel  Irhoud. Has this egg-shaped brain case but is as   recent as roughly 13,000 years old, that's roughly  when this person lived. This complicated picture   of different alleged homo sapiens with with  a variety of features is made all the more   complicated by the fact that we know that other  distinct archaic forms of humans lived in Africa   at around the same time. Homo naledi lived around  236 to 335,000 years ago and seemingly is a much   smaller form of hominin. We also have this Kabwe  skull which is considered a homo heidelbergensis   and has, you know, really archaic features dates  to only 300,000 years old as well. How all these   different groups of hominins interacted and  what role they played in our evolution, in the   evolution of homo sapiens is not known. There is  some genetic evidence that homo sapiens interbred   with an archaic human around 124,000 years ago  in Africa but it's it's a very recent study and   the implications of this result are not well  understood. Is the skull from Iwo Eleru a late   survivor of one of these archaic forms of human  or is it just that homo sapiens in this region   retained some archaic features much longer than  anywhere else? It's really hard to answer this   question because we just have one skull with  no genetic tests. So we have absolutely no   idea of the context that Iwo Eleru lived in,  the context that they evolved in. The skull   from Nigeria is an interesting outlier though, in  general what we see in the archaeological record   is a clear progression from egghead to tennis ball  head. So what parts of our brain were changing   and developing that caused this change of shape  and what can that tell us about our evolution? Let's look at two brains, two endocasts  from our evolutionary history.   One from three hundred thousand years ago,  Jebel Irhuod, and a modern human. These brains   are roughly the same capacity, there's not much  difference in size but they have been reorganized,   they have changed shape. So what parts grew  and developed and what can we deduce from that? "two features of this process stand out periatal  and cerebellar bulging. Parietal areas are   involved in orientation, attention, perception of  stimuli, sensory motor transformations, underlying   planning, physio spatial integration, imagery,  self-awareness, working and long-term memory,   numerical processing, and tool use. The cerebellum  is associated not only with motor-related   functions like the coordination of movements  and balance, but also with spatial processing,   working memory, language, social  cognition, and effective processing". Clearly there is an evolutionary  pressure an evolutionary advantage   in increasing our creativity, increasing our  perceptions, increasing our adaptability.   This might seem an obvious thing to say  considering the vast amount of creativity   we're surrounded by every day... like this  wonderful youtube video, the highest form of art. "oooooh i'm an artist" It is really interesting to think about this  brain development though. This progression from   egghead to golf ball head over the past 300,000  years is mirrored in the archaeological record   by an increase in creativity by an increase  in the sophistication of tools. The people   living in Jebel Irhoud 300,000 years ago probably  didn't have no creativity, no symbolic expression   because we see, you know, engravings  on shells from 500,000 years ago   that were created by homo erectus. It's not  much but it shows that these archaic humans,   there's something going on up there there's  a spark, there's a creative spark. By 100,000   years ago, you know, we're starting to see much  more rounder skulls in the archaeological record   and we see the development of really specialized  bone tools like this harpoon from the Congo. We   see in South Africa real great evidence for art  and symbolic expression from ochre and carved   ostrich eggs and jewelry made from shells. Moving  forward in time by fifty thousand, forty thousand,   thirty thousand years ago this globular brain  shape is, other than a few outliers, absolutely   ubiquitous across homo sapiens and the evidence  for symbolic expression and specialized tools   is overwhelming. No one could look at the art from  this time period and think that these were just   simple cavemen. Nothing could be further from  the truth. No archaic human ever quite reached   the level of creativity and symbolism that we  see produced by modern humans. Even though our   opinion of neanderthals has changed dramatically  over the past 30 years, you know, they were very   intelligent, very sentient humans, truly humans  yet they did not have this globular brain shape   and they didn't have as well a developed artistic  expression. So even though our brains didn't   really increase in size this reorganization seems  to have been absolutely key to our development. "um i am a glob globby glob  globby globby head artist" that's why humans are man  we're globby globy artists. The genetic evidence for our evolution in Africa  is is overwhelming, it's almost undeniable.   Obviously everything is subject to change  but this evidence is really overwhelming,   it has to be said. African populations  have a higher genetic diversity   than anywhere else in the world and the further  you move away from Africa the more that genetic   diversity declines. Now I don't want you to get  offended, or get hurt, or get worried, i'm not   accusing everyone outside of Africa of being one  giant Hapsburg dynasty, there's plenty of genetic   diversity to go around. But this does illustrate  that Africa is almost certainly the place that   we evolved in. In biology this is called the  serial founder effect. If you had a region   where a species evolved, that region is going  to contain the entire genetic diversity of that   species. If one group breaks off and moves into a  new region, then that new region can only contain   the diversity of the group that split. This is the  pattern that we see in the archaeological record.   Africa high diversity, outside of Africa lower  diversity. We don't just use the serial founder   effect to discuss our movement outside of Africa,  it's a really key tool that anthropologists and   geneticists can use to trace human migrations.  Let's look at mitochondrial haplogroup L3.   A haplogroup is basically a a line of descent,  a lineage that you can trace back to one person   deep in pre-history. So mitochondrial haplogroup  L3 are the living descendants of this L3 woman who   lived way back in time. The L3 haplogroup is found  widely across sub-saharan Africa and interestingly   to this whole debate it is the haplogroup that  every ancient fossil that we have dna from outside   of Africa descended from, and it is the haplogroup  that every non-african haplogroup descends from.   Let me repeat that, that's worth repeating.  Every mitochondrial haplogroup outside of Africa   descends from L3, every single one. If you are not  an African you are a descendant of this L3 woman,   who was almost certainly African. No ifs, no  butts, no coconuts from Australia to Aberdeen   and everywhere in between you are a descendant  of this L3 woman, and even if you are from Africa   there is also a very strong chance that  you are a descendant of this woman too. Stefan from the future here, quick  interruption. I shouldn't have said no coconuts,   there are always coconuts with these things our  evolutionary history is not straightforward.   In this particular situation the coconut  is not whether you are related to L3 woman   but the coconut is whether L3 woman did live in  Africa there is some debate as to whether humans   had already left that Africa by that point and  we're in western Asia or maybe even south Asia,   India. If that is the case, if L3 women had  already left Africa, that wouldn't negate the fact   that we had evolved there it would just mean  that we had left earlier than we currently   realize. There's always coconuts, I shouldn't  have said that there are always coconuts. Now mitochondrial DNA, is just a very small part  of our entire genetic makeup but this has been   confirmed time and time again. In 2016  a study combined literally hundreds of   genetic tests to create a phylogenetic  relationship of humanity. The pattern is   the same guys Africa is at the core  of our DNA. If that wasn't enough,   we don't just see this pattern in our genetics we  also see it in the genetics of bacteria that live   within us. Helicobacter pylori, i think that's  how you say it, is a bacteria that lives within   our guts and causes stomach cancer and ulcers and  stuff like that. It's really an absolute bastard   but nevertheless lives within us. We see  the same pattern of genetic diversity.   Helicobacter in Africa, high diversity, outside  of Africa low diversity. This suggests that this   bacteria was present in the homo sapiens that  first left Africa and as a result suffered a   loss of genetic diversity just as us homo sapiens  did. Which is really fascinating. I if you are   suffering from stomach cancer i am sorry, I truly  wish you a speedy and painless recovery, but it is   genuinely interesting that we can learn about  our evolution from that, that is crazy to me! So as it stands at the minute, the earliest  fossils that we could describe as homo sapiens,   archaic homo sapiens, come from Africa  and the genetic evidence overwhelmingly   suggests we evolved in Africa. That's a  huge region though, can we narrow it down   further is there one specific place in Africa that  we evolved in? That is a highly debated topic.   If we look at the fossils that we've already  mentioned, Jebel Irhoud, Herto, Omo, Qafzeh, plus   a few others Florisbad in South Africa, Laetoli  in Tanzania, Guomde in Kenya, there is a huge   pan-african distribution of these alleged homo  sapiens. I say alleged because not everyone agrees   on their classification but these are basically  the contenders for archaic homo sapiens. The only   region where it seems like there's a bit of a gap  is west Africa but that is the least well explored   archaeologically so it is quite likely that that  is just a bias in the archaeological record.   Either way though north to south there is a  huge distribution of these archaic homo sapiens.   Considering this distribution it might really  be hard to find one particular point that we   evolved in. This is the same in the genetic  record different studies have come to different   conclusions about whether south Africa or  east Africa or west Africa or central Africa   were the original home place of our species but  again it's just hard to untangle the genetic   relationships between these groups that are  constantly mixing. I explained earlier that   a haplogroup is is a line of dissent from one  person in in pre-history, well we can push that to   its logical conclusion, it's extreme conclusion  and discuss the two people that every human   on the entire planet is descended from we call  them mitochondrial eve and y chromosomal adam. These hypothetical people lived around 200,000  years ago. Let's say we found the region that they   lived in, that's not necessarily the birthplace  of all of humanity, these are just two people   whose genetics by probably absolute chance  have survived until the present day. It's   not necessarily the first homo sapiens,  where they lived is not necessarily   the home region of our species. So to  summarize even though anthropologists   and archaeologists are very confident that  we evolved in Africa what we mean by that   and exactly how that evolution took place is  still quite obscure and very highly debated.   It does beg one massive question though if  we evolved in Africa ,when did we leave? 60-ish thousand years ago, if you're not  African that's when your ancestors left   the continent. This estimate isn't based  on archaeological evidence though, really,   it's based more on genetics. Remember  mitochondrial haplogroup L3? That   branch of our family tree, that lineage formed  around 60,000 years ago. Or between 59 and   79,000 years ago and puts an upper limit on our  migration out of Africa. Certainly our ancestors,   your ancestors did not leave that continent  before 79,000 years ago. That stomach bug i   mentioned earlier, that divergence and their  genetics occurred around 58,000 years ago and   other genetic studies have put a migration out  of Africa at around 55,000 years ago. So multiple   genetic studies are all converging around roughly  similar dates, let's say between 55 and 70,000   years ago, our ancestors left Africa. This is  great, this is all fantastic evidence of course.   There's one small problem though, archaeologically  we seem to have evidence of homo sapiens outside   of Africa much, much earlier than that. As  I mentioned earlier, we know homo sapiens   were living in the Levant between 90 and 120,000  years ago and a new study, hot off the presses,   just released, has shown that there were multiple  migrations into western Asia within the last four   hundred thousand years. This region is right next  door to Africa though, it's just a short hop, skip   and a jump. In the north it is uh connected to  the continent and in the south the strait between   Asia and Africa would have been only between  sort of 4 and 15 kilometers wide in pre-history.   You could see Asia just over the shore, you could  swim it, probably, if you're a good swimmer.   So really this south west region of Asia was home  to many hominins, many humans, many homo sapiens   during our evolution. Now it is very dry, very  deserty, but there were lakes and rivers in this   region periodically and it's only natural  to believe that humans just were following   their climate, following the resources they  needed, following the food that they needed,   and spent long periods of of our evolution in  western Asia. However, western Asia is not the   only region that we find very early homo sapiens  remains. Archaeologists found a homo sapiens   cranium from Apidima cave in Greece which dates  to around 230,000 years ago. Homo sapiens teeth   have been found in China. Their dates are between  80 and 113,000 years ago. We were in Sumatra by   70,000 years ago and the north coast of Australia  by 65,000 years ago. Those last two are within the   sort of window of out of Africa suggested by our  genetics but they're right at the top end of it,   we really would have had to have dashed along the  south coast of Asia to get there by those times,   which is possible but still we have those remains  in Greece, we have those remains in China,   we have a lot of hominin tools in India  that we haven't been able to pin on someone.   So how do we reconcile the tension between the  genetic evidence and the archaeological evidence? The first possibility is that we have missed the  genetic signals of these earlier migrations. In   2016 geneticists reported a previously undetected  genetic signal in the genes of people in   Papua New Guinea that suggested that they had a  contribution to their DNA of homo sapiens around   120,000 years ago. It was just a tiny fraction of  their DNA, around 2%, so they are certainly still   predominantly relatives of that later migration  out of Africa, but it is possible that we   we have missed these earlier genetic signals  of an earlier migration. However other studies   knowing that geneticists had come to this result  tried to to replicate it and and so far have been   unsuccessful. So at the minute it's really  up for up for debate, it hasn't been proved   at the minute that we have this genetic signal uh  within us from an earlier migration out of Africa. The other explanation therefore is that  these earlier migrations of homo sapiens   out of Africa have not left a lasting genetic  legacy, they weren't really our direct ancestors,   they weren't ultimately successful you could say.  This raises a lot of questions. If homo sapiens   expanded out of Africa, but died out before this  later migration at 65,000 years ago, why did they   die out and other archaic humans like neanderthals  and denisovans survived? If these communities   of homo sapiens survived until this later  migration, then why don't we see more evidence of   interbreeding between these two lineages of ours?  Especially considering the abundant evidence we   have for interbreeding with other archaic humans?  That does raise questions, if they survived until   that point that is an interesting question. We  know from studying archaic DNA within Europe and   early European fossils that we are not really  a close relative to the first europeans anymore   that there has been a lot of population turnover.  So these things are are possible, it is certainly   possible that these earlier migrations died out.  Whatever caused that expansion of homo sapiens   between 55 and 70,000 years ago to be successful  it's clear we absolutely burst onto the scene   we we kicked the door in we rampaged  around the world like an invasive species. We reached australia by 65,000 years ago Europe by  47,000 years ago the far northern coast of Eurasia   by 45,000 years ago, North America by 24,000  years ago, maybe even earlier, highly debated.   Everywhere we went populations of large animals  seemed to die out soon after. We absolutely went   wild, there's no question about it. What gave us  that killer edge? What allowed us to expand like   that at the expense of everyone else and to be  so much more successful than any other archaic   human, any other earlier migration of homo  sapiens? It could have been our technology. "One reason why humans failed to settle  more permanently might be competition.   Perhaps the presence of neanderthals and other  human populations in number was a key reason   behind this? I think this might be one factor,  but not the single explanation. I think it is   more likely that before dispersing into the wide  range of environments in Eurasia, homo sapiens   had first to develop a gamut of new and improved  technologies in order to survive and prosper". 48,000 years ago in what is now southwest Sri  Lanka, a group of homo sapiens called this   dense rainforest home. The rainforest really  is a is a very different environment to the   grasslands of Africa that we seemingly  evolved in. Even though it's very green,   very lush, it's not an easy environment  to survive in. But nevertheless this   group adapted. Archaeologists have found a trove  of arrows made from the bones of monkeys that   these prehistoric homo sapiens left behind. One  of the arrows even has lines engraved on it which   ethnographically other hunter-gatherers have used  to attach poisons to arrows. It's possible that   that some of these other bones were used as darts,  that's another possibility. Technology like the   bow and arrow must have been a very important part  of their survival strategy, it's very hard to hunt   the small and agile game that live in the the rain  forest, live in the canopy of the jungle, without   these quick, fast weapons. The earliest evidence  we see of bows and arrows in the archaeological   record come from Africa interestingly between  60 and 70,000 years ago, right on the cusp of   our migration. It's fascinating to me that this  community of hunter-gatherers in the rainforest,   hunting monkeys with their bows and arrows, were  contemporaries of the humans that were living in   the far north of Siberia, the far north of Eurasia  who were hunting mammoths and huge game like that,   and living in a wildly different environment.  These two groups of homo sapiens were closely   related, their ancestors had left Africa maybe  only 15,000 years before. Yet one group went north   and adapted to the cold, one group hugged the  south coast of Asia, adapted to the rainforest.   This level of flexibility is only seen in  modern humans, not in any other archaic human,   not in archaic homo sapiens, not in neanderthals,  not in denisovans. They adapted by following   their preferred environment as the climate changed  around them, this later migration of homo sapiens   was able to adapt by changing their lifestyle.  In times of climatic variability, we were still   able to expand, they contracted. We don't see any  evidence of neanderthals or anyone else producing   technology like bows and arrows, atl-atls, blow  guns they just seemingly did not produce them. This is honestly my seventh or  eighth attempt at ending this video,   because I feel like I should say something  profound about our evolutionary journey but   I just, I just don't know what to say.  I don't know what profound thing to say.   It's so hard because the point we're at in  this video where i'm sat on this log right here   is about 30,000 years ago. Humans, homo sapiens,  have spread across the entire planet. All our   archaic cousins have either been absorbed into  our communities or are dead. After 30,000 years   ago it just seems like they're no more and yet  even though we've been on this journey for a   million years by this point, this is the start  of human history, what we consider like the   upper paleolithic, the mesolithic, neolithic,  on and on and on through time. The video ends   at the point where all of human history kind of  starts. So I just uh i don't know what to say,   i don't know what profound thing to say so  I'm going to steal that quote from Winston   Churchill. This is not the end, it's not even  the beginning of the end, but it is the end   of the beginning. Thanks for watching guys loads  more videos on human evolution, pre-history,   our story to come there's so much more  to say and uh i appreciate you watching. Boop!
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Channel: Stefan Milo
Views: 90,533
Rating: 4.9183002 out of 5
Keywords: History, Archaeology, anthropology, folk tales, stefan milo, american history, ancient history, world history
Id: iM6LSUpanmg
Channel Id: undefined
Length: 40min 45sec (2445 seconds)
Published: Fri Sep 17 2021
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