Of course more fossils will change our ideas, just as we now look back on the book from 1965 with different opinions. But I do think this theory 'has legs' (badum tsss) What do you all think? Huge thanks to Prof. DeSilva for his help! Check out his brilliant book here: www.amazon.com/dp/0062938495/ref=cm_sw_em_r_mt_dp_MMN6K0SR2C9A98CCJ7BG
Omg. I was born in '62, and my mom brought me that Time-Life book on human evolution. Even though I was too young and the text of the book was beyond me, I was fascinated by the idea of evolution. I took the book with me the first time I went to summer camp, instead of a stuffed toy or security blanket.
@@StefanMilo Your videos are quite well done, brother, but I would not buy them because they are so directly derived from what I call the 'standard evolutionary textbook'' (SET) paradigm...which holds that 3.4 mya Lucy was our Pliocene ancestor, even after Ardi turned up.. it is a belief held only by the American Chicago-based paleo-theorists, not English people like the Leakeys, or the French paleo-anthropologists. I wish you would have a decent photographically based look at the 6 to 5.7 My footprints found on the seashore of Crete by Gierlinski et al 2017 (it took them 8 years to get their paper published), and cover Attenborough's treatment of the aquatic wading theory of how we became obligate bipeds. We did NOT come down out of the trees, no, our descendant lineages of orangutans, gorillas and chimps moved into the trees and became much more arboreal, frugivorous apes. It is actually far more logical to believe that some wading, sedgivorous australopiths became chimpanzees, and the larger paranthropus sedgivores became gorillas. That is why we have never found any old chimpanzee and gorilla fossils.
There seems to be a rule of human history, that "Everything Was Earlier" (than the classical account). The more we discover, the earlier everything gets: writing, domesticating animals, understanding the stars...
I think part of that is because there's this bias that early humans were dumb. They weren't. They're just as smart and observant as we are today. We just have a wealth of knowledge at our fingertips that they didn't.
it’s not really a rule, and i think a distinction should be made. people like to signify the oldest stuff *known.* no one is saying we’ve found the oldest writing, but there is writing we have that is the oldest to us
This makes a very good point. Knuckle walking is not an obvious form of locomotion and would be more likely to be a specialist adaptation for a larger primate. The example of the gibbon shows very well how our distant ancestors may have walked and then as those which eventually became hominids chose bipedalism, others adopted a different method.
The possibility that knuckle walking evolved 2 separate times was especially interesting to me. I love the content you are putting out. Thank you, Stefan!
It makes sense, when you think about it. Quadrapeds are more stable than bipeds. You'd only expect bipedalism to stick around if there was a good reason for it (maybe like increasingly heavy dependence on tool use).
It is probably a vast array of causes. The natural habitat for both apes is a heavily forested, as well as having small shrubbery. What do humans do when we're going through a low tree line? We squat lower to avoid from getting our faces hit by branches. The amount of times you squat low rises, might as well always walk in a lower posture permanently. If climbing, you want a stronger base of 4 limbs on the floor but be ready to grab onto something quickly. In that case you might adobt walking on knuckles instead of palms as your hands are in a much more natural position to grasp at trees, rocks, etc. Just my 2 cents.
I thought bipedalism evolved back with gibbons (lesser apes), but to avoid competition with bipedal apes the asian apes went arborea and the african apes adopted knuckle walking?
When I was a kid, before I started first grade, my neighbor who had just returned from the Vietnam war handed me that book one summer afternoon and told me I could keep it and that I should read it someday when I am able to read. That was the summer before starting Catholic school, and I eventually took that book in for show & tell. I got sent home, with a beating from a horrible Nun who had a beef with Darwin. And that solidified my love of that book and everything in it.
My disillusionment with Catholicism started in the first grade. I had recently lost my dog and when we were being taught about heaven I asked the nun if I would see my dog again if I went to heaven. She said "no, dogs do not go to heaven". Not sure I was as interested in the whole thing after that.
It's funny because I remember some creationists (both Christian and Muslim) who said apes evolved from sinful degenerate humans, so they should love this theory!
I dont know why, but i'm blown away by the notion that there were apes essentially all over Europe. I had just just always assumed apes = jungles = equator = Africa.
Apes have to be around fruit trees And away from humans to survive and grow.. they have had millions of years to grow in this Darwin theory and they never have proportionately they are stuck on that little piece of land that God put them on as primates he did not put them in the North Pole with polar bears or in the desert with camels supposed to evolution theory is false and fake on the climatic environmental theory alone
I was the same. Then I searched up climate during the Miocene and it all made sense. Later, when homo erectus left Africa and went to what’s now Georgia 1.8 million years ago (and to China even earlier), Georgia had a Mediterranean climate.
@@aleanbh3808 old HEBREW documents Suggested Africa was batren of western mankind until Hebrews punished a wrongdoer by banishing him to the humanless African jungles, where he mated with now extinct 6 foot wallkings apes, this hints at Africans being the missing or lost tribe descendants of the original tribe member banished to humanless documented jungles south of the Middle East,, Over centuries Evolution of this inbreeding has populated the Continent,. or are we to Believe Africans here as long as non Africans and they wouldn't civilize as population to the north and or other continents & people's?
Actually, this has been the theory of a French paleoanthropologist for at least 10 years now: Pascal Picq. He wrote a few books about it. His theory is that the last common ancestor of human/chimps lived in Eurasia, which would account for the existence of orang-outangs and gibbons. When the forests started to recede in Europe, some of these primates moved back to Africa and other to Asia. There was also a documentary on this topics on Arte, based on the theories of Madelaine Böhme in 2020.
there are some indications there were fossils found of apes in Eurasia, but those was far more basale than the common ancesters of the chimps and humans and in fact far more primitive the the whole ape line, including the oldest African ape Ekembo. They are very hard to distinguish from monkeys.
Found and skimmed some old history books from the 50s and 60s in the past. The differences a few decades make can be surprising. Makes me laugh when people say, "the science is settled". It's regularly changed and adjusted.
Stefan, I'd known that the famous art at the beginning of the video had fallen into disfavor among the paleo cognoscenti, but this video is the first to fully explain to me why that is so. Thank you.
Well one thing that I didn’t mention is that many blame this image for the misconception “if we evolved from apes, then why are there still apes”. They blame this linear representation of evolution for that misconception because it doesn’t accurately portray the fact that we didn’t evolve from chimps, but we share a common ancestor.
@@StefanMilo all people has to do is read Darwin's books or read alfred r. Wallace (the pete best of biology). But they won't read them, they just follow. Darwin didn't replace al but the impact and news coverage was the same. Darwin had his evolutionary theory first but took forever to get the book going, i believe if alfred hadn't contacted Darwin, Darwin may have died before he published origins. I wish you could do a video explaining a scientific theory, the non evolutionary believers always say " it's a theory so it's not true". Please explain why it's called theory. I get tired of trying to explain to people posting that, I'm glad you covered " we didn't evolve from apes". They would know if they just read the books. Anyhoo, very good videos. 👍
@@adamrodaway9116 It's neither progressive, nor linear. The figure excludes all the lineages that ended extinct since our split from chimpanzee's ancestors
That book,"Early Man",was one of the joys of my life around age 10 to 17. Stunning artwork in there. The whole 'Time/Life' series was awesome. My concurrent budding interest in Comparative Religion made for a vibrant,if confusing, intellectual life. My youthful passion for dinosaurs and anthropology makes me fully appreciate what we've learned in just a few decades. Questions remain,but so many have been answered. This is a great channel!
The ape-men were not human ancestors. They were the result of human-ape hybridization, probably in Genesis 6 : 12. The DNA of Neanderthals and Denisovans was 15-16ths human and 1-16th chimpanzee.
I recognized that book instantly and then had the jarring experience of it being called a textbook? I LOVED the time/life books, the Universe and Mathematics were my favorties.
@@StefanMilo Don't worry man! And thanks for the awesome video. I have learned so much from your content and also challenged a few things I previously believed :).
Your videos were always among the best, but you've transcended that over the last year. These are in a league of their own and I'm so thankful you're making this content. My next video briefly mentions this same thing as it is going to be a dissection of a recent "out of africa debunk" video that brought up Ardi and Lucy- I'll have to mention this video for further learning!
Zeke,I hope you’re in agreement with debunking the “out-of-africa” theory. The 1990s study that blew the theory up was intentionally misinterpreted, twisting the researchers’ words/research. It was done by the media et al to give the “out-of-africa” theory legitimacy, in order to make the study fit in with the Afro-Centric movement that was being pushed. The researchers themselves have written about it, and what their research/paper _ACTUALLY_ says, but the damage had already been done. Anyways, I agree with Red Riding Hood here - nice plug lol. At least it’s good to see that your two video titles reflect you know humans origins consisted of multiple species (but only the brave scientists will admit that there are still more differences in human groups today than what is needed as requirements to prove an animal group is a sub-species).
Stefan, you are an extraordinary science communicator! Your ability to handle both complex scientific topics and to humanize even our most distant ancestors is singular. Love what you are doing and am excited every time I get a notification that a new video is up. Edit: The quality of your videos has improved so much in the last year or so. Have you approached Nebula? Hell, I think your recent videos are matching the quality you see on Curiosity Stream. Would love to see you on additional platforms.
@@Where_is_Waldo Most Nebula creators still do UA-cam (to the best of my knowledge) and either release early on Nebula or include less algorithmically successful pieces exclusively on Nebula. But Nebula and Curiosity Stream are like $13.00 (both) yearly! It's the best value paid media out there.
What l find fascinating and also incredibly frustrating is when a certain group of people declares that scientists are arrogant and pretend to have all the answers when the exact opposite is true. Just because science and evidence disagrees with your worldview doesn’t mean science is wrong or presumptuous. It means you have to be humble and revise all your premises. Unfortunately, that seems to be a step too far for many people.
I loved your videos from the start, but I have to say you keep improving them by leaps and bounds every time. This was fascinating and brilliant, and I have to say Prof DeSilva is an excellent science communicator, too!
Incredibly interesting! The thirst for the true history of things is sometimes a curse. All we can do is take our best guess on what little we are given. Thanks so much for a very entertaining video.
But think about it... Just in my lifetime we've gone from this march of progress idea to this theory that we were already somewhat bipedal. We've discovered so much and developed new technology at such a fast rate in a relatively short amount of time. Who knows what we'll find out next?
I am a 1961 vintage human, this book blew my mind at around 1967. A bit dated but I still have it and a few more from that series. I discovered science
Love your videos Stefan. I always rewatch a few older videos after you upload - I love the way you tell a story and produce your videos. A true gem on UA-cam.
I find the hand bones interesting, because I broke my hand recently. They said my hand bones were significantly thicker than most people they had seen. (Citation below) Probably not surprising, since I climb trees for living and have for quite some time now. Edit: to clarify one issue in physical anthropology is often differences that often are assumed to be genetic, might be developmental “Prior exercise significantly correlated to cortical thickness (r = 0.13; p < 0.002) and periosteal circumference (r = 0.18; p < 0.005). Cadets in the highest exercise group had 5.8% higher cortical thickness compared to those in the lowest exercise group (p < 0.04; Figure 1).” Determinants of bone mass and bone size in a large cohort of physically active young adult men Nutrition and Metabolism 3, article 14 JA Ruffing et al Feb 15
I was going to say something similar. My mom was born with one leg substantially longer than the other. As a result her big toe on the short leg side is three times the size of the long leg side. This is because she is always supporting that side with only her big toe while being flat foot on the other.
@@frankconley7630 well I don’t have any real data to back it up. But, my hands and certainly my knuckles seem to have gotten significantly thicker, while the rest of me hasn’t. That said people in my industry tend to get retired from the field due to shoulder, and elbow overuse injuries. So while we might be able to adapt to some degree, we obviously are limited genetically
I heard it can support higher weights and possibly allows for stronger arms wich would be useful in interspecific competition i guess , But to be honest i don't know
Honestly this and crocodiles having warm blooded metabolisms are two of the biggest paradime shifts in the field of paleontology : They basically flip the whole idea of what an advanced animal should look like , we assumed us and birds where evolved and advanced because of our bipedalism and higher metabolism so obiusly chimps and crocs are the lower step the less advanced creatures , Then we realize crocodiles where also warmblooded long ago and they became cold blooded because they didn't start as ambush hunters , And chimps evolved knucle walking while we where on our march around the world making turtles extinct , So yeah there is really no up or down in classifying species only left and right , r and K strategists , High metabolism or low metabolism , I type survival curve or III type survival curve Neither one is superior to the other , both are better in certain situations
Loved that 1965 Time-Life book. It was one of the things that set me on the path to understanding human evolution, and getting a degree in Anthropology. I now have a pdf copy of the book.
That makes sense. I've always despised recreations of our ancestors showing them as clumsy, hunched over bipedalists. They were as upright and graceful at it as we are today.
13:30 if you spend a bit of time in the forest you will realize that knuckle walking is an adaptation to aid in getting through thick brush. Standing upright is very difficult for getting through the tangled branches that often spread out upwards, but are more sparse down low.
Correct ... Then if you go into the open ~plains of an area, up-right walking is as good or better than knuckle walking plus gives much better vision of your area.
I still have that book on Early Man from 1965. It was my favorite book my collection of the Life Nature Library books. I studied that thing over and over. I love that the video opened with it.
I loved this Time-Life science series that included "Early Man." I read them all religiously when I was 11 and was particularly fond of "Early Man", "the Universe" and "the Mind". In a different time when knowledge was cloistered, it was an introduction and a keyhole into a dozen different scientific domains.
I grew up with those Time Life books; I remember the one called The Mind in particular. I don’t think we had them at home but we would often get them from the library. We were Catholics but my parents had no quarrel with anything to do with science. We kids had a subscription to a children’s version of the Time Life series; they were wonderful books too. All kinds of topics, from dinosaurs to shipwrecks to one on spiders with huge closeup pictures that we would dare each other to look at. I kind of wish we’d kept them all.
@@KathyPrendergast-cu5ci A lady at my Mom's church gave her many boxes filled with this series of books. For an average curious 10/11 year old child, it was a solid introduction to life sciences, physics, astronomy, social sciences, archaeology, the history of math and philosophy in broad strokes.
I can't explain it, but seeing Dr. DeSilva holding Sahelanthropus makes my chest ache. I don't know how to describe it. Curiosity? A connection? Some weird, misplaced sense of nostalgia? I can't fully put it into words, but I think it feels... right.
Good video. The idea that knuckle walking is the new adaptation seems reasonable. What I've noticed when I've been on crutches, when I use my hiking poles, or when I climb up rocks or a stair, engaging four 'limb' movement is faster, more secure, more versatile. In Japan those really steep traditional home stairs? If there's anything at all I can grab on to with my hands (and I only need 2-3 points to go up a full story) then I'm rapid (I think it's the fastest way for a human to climb. Ladders and regular stairs are slow in comparison) and it's secure; same going down. So knuckle walking has a lot going for it, unless.... you live on a open savanna for a million or 150,000 years or need to cross distances on reasonably flat ground, and somewhere along the way you start using a lot of hand tools.
I just came to this channel and I'm so incredibly in love with it. The sense of humor, the content, the video style. Ugh I'm subbing!! I'm so happy I found this channel!
I’ve been fascinated by ancient hominids etc since reading Richard Leakeys book Origins.. he described finding “The Turkana Boy “ about 2 million years old and postulated how he might’ve lived and more importantly to me, died. I was hooked, and hence why I’m delighted to have found this series… nice one ☝️🏴
A theory suggests bipedalism evolved from knuckle walking because hominids had to start rising upright to look over tall grass. What if instead knuckle walking evolved because of the environments the knuckle walkers found themselves in - densely packed which would've made for constant ducking if bipedal, and walking on four limbs gave them more balance on tree branches? If the forests became denser and denser maybe their ancestors went from crouching all the time to knuckle walking. And it grants more stability for carrying infants on their backs. Knuckle walking would still allow them to use their hands for minor tool manipulation and tree climbing, rather than their hands simply shrinking to be more paw-like. It's so fascinating to ask
Great video. Bipedalism is rare in mammals, but so is knuckle walking. What would the selective presssures be to evolve knuckle walking? Maybe it helped chimps become more arboreal, but just how arboreal are gorillas? The male gorilla is huge, and I don't know how arboreal they actually are.
Last year I heard that the ancestors of chimpanzees had hands more like our hands. It is good to see more openness to data rather than sticking to a narrative based largely on supposition.
@@kmadge9820 Remember gorillas split off from the common ancestor of humans and chimps. So either the similarities between chimps and gorillas is the result of common ancetry or convergent evolion. If it is convergent evolution, what were the selective forces driving this? If these similarities are due to an arboreal lifestyle, then what drove gorillas to become to large?
@@davidwood8730 I didn't mention gorillas. I pointed out that the common ancestor had hands like ours, not chimps, and chimpanzees' hands are a refinement consequent on arboreal life. Most likely reason for chimpanzees being relatively small and light is that it's advantageous in climbing tree tops and escaping predators. Gorillas live mainly on the ground and their advantage is in fighting predators.
@@GhostScout42 Yes, it doesn't seem likelly our common ancestor was that large. What selective forces caused them to grow and abandon an arboreal lifestyle? They can't have left the trees that long ago because they retain so many arboreal adaptations.
It might be unrelated at all, but one of the things that came to my mind as you were discussing feet shape, was leg disorders in babies, where most common is curled in feet (resembling our tree climbing relatives imo) - can/does this tell us anything about our evolution?
@@62Cristoforo ya, i know it's hypothesized in embrio, at the same time we human love finding connections ;) Looking farther at this, i found two different phenomena in babies: first is Toes Curling - which is part of normal development (looks to me like "grasp mom/tree" reflex hh). second is Pediatric Bowlegs, which usually is also considered normal in infancy (and usually fixes itself when infant starts walking and putting upward/standing weight on their legs). Interesting stuff.
Dude, we had that Early Man book in our house when I was a kid! Ever since, I've been fascinated by what we (incorrectly!) called "ape men" or "cave men", and wondered what their day was like when they woke up each morning. I knew they were biologically close to us, and that their brains must have been much like ours, but I knew that their bones told of often horribly injured, broken bodies, and incredibly tough lives. That contrast between intellectual consciousness and physical brutality was just mind bending to think about.
I’m thinking that so-called “cavemen” didn’t live in caves. They just liked to explore them and leave art on the walls. Their lifestyle may not have as brutal as you suggest- think of tribes of Native Americans. Some of the early European settlers left their settlements to join those tribes.
Fun fact, The scientific name for Chimpanzees is Pan troglodytes. The word troglodytes literally means "cave dwellers". Guess where no chimpanzee lives
@@darko714 which is exactly why hearths are excavated in caves and the remains of cooked flesh dating back to the, you guessed it, STONE AGE and Cave Men and Cave Women.
Good thought provoking video. Could be that knuckle walking evolved because of the environment and to relieve back stress. While in the trees apes and chimps undoubtedly developed large upper body strength and mass, long/ longish arms and great pecs. While their lower bodies developed some but just couldn't keep up with their upper halves. So when they got on the ground with all of the underbrush in the forested areas they probably had to crouch and crawl to get to a clear spot and when they stood up they were probably good for short distances but then their upper body mass and weight would put a lot of strain on their lower backs so they would lean forward onto their hands. They heavily relied on their hands and arms for locomotion in the trees they just continued with that when they were on the ground.
It's so refreshing to watch a well-researched scientific lesson. No ancient aliens, no bizarre theories - just science. Thank you! (Side note: I still have a copy of that Time-Life book!)
@@earlysda You can't "see" an atom but we know it is there. You can't see the wind and yet there it is. Since no one is around for a few million years to observe, we rely on a range of indirect proofs of evolution - bone fragments (and most recently, DNA analysis for a limited group of samples). We don't always know HOW evolutionary changes happened, but it's clear they're real.
@@rgnyc R G, You are years behind the times. Yes, we can see atoms. . Evolution has never been observed while it's happening. . That means Evolution fails the scientific method.
@@earlysda we have definitely observed accelerated (macro) evolution in a multitude of animals. And what you said isnt true whatsoever, definitionally we cannot observe blackholes or the big bang but via indirect evidence and inference we can gather an understanding of these things. Under your view electrons, black holes, the big bang, gravity and virtual particles arent scientific concepts. We cannot directly observe any of these phenomena but can see their existence through their effect on things around them.
I had that book when I was a child back in the 1960's. Though the evidence we have now makes it clear that much of what was in that book was incorrect, it did get my interest in paleoanthropology going, and at the time, it was right up to date with what the thinking was. It is really amazing to see how far our knowledge has progressed in just in one lifetime. There can be no doubt that there will be further changes to our knowledge, and more fleshing out of the whole picture as time goes on, and I envy the currently young people who will be around to witness it. The world is a fascinating place, and for the curious, ten thousand years would not be enough to learn/see it all, yet on average, we are granted only seventy-five years enjoy it and drink in as much of it as we can. Such a precious gift we have. Do not waste it.
The science of paleo is in constant change. Which makes it very exciting as well as very confusing. With many having their own interpretations. It is one of the fields we may never know the full truth about. I found this piece informative. Thank for putting it together.
"Were We Wrong" always strikes me as click-baity when it comes science news story headlines. New data generates new hypotheses or eliminates old ones. That is what the modern scientific process is all about - figuring out how we got things wrong previously.
Excellent, I have been trying to make this same point to students. We didn't evolve from chimpanzees, both chimpanzees and we have been evolving from something different from both of us to arrive at our current forms.
Well put. That is an obvious but often made mistake....I also think we should look at a semi-acquatic, continually wading scenario....forget the trees, most fruit trees had not evolved until the Late Miocene.
I've been saying this for several years now, for many of the exact same reasons. Everyone should read the paper called _The arboreal origins of human bipedalism_ for a better understanding of this. They talk not only about the fossils discussed here, but the fossils of even earlier hominoids, so-called "crown" hominoids that lived with an upright posture in the canopy of the trees as long as 20 million years ago, and which are the ancestors of all living apes. *_«By the early 2000s the fossil record of the Eurasian and East African Miocene (23-5 million years ago (Ma)) was burgeoning and revealing the body form of early ‘crown’ hominoids ('crown’ hominoids being the direct ancestors of all living apes, including humans). These included fossils of species such as Morotopithecus bishopi (from approximately 18-22 Ma), Pierolapithecus catalaunicus (c. 12 Ma), Hispanopithecus (Dryopithecus) laietanus (c. 10 Ma) and Orrorin tugenensis (6 Ma). These fossils suggested that, contrary to expectations and fossil evidence from Proconsul hesoloni and associated species, the early crown hominoids stood and moved with an orthograde (upright) posture._* *_[...]_* *_The fact that orthograde (upright) body postures had been evolving and diversifying in our hominoid ancestry for in excess of 15 million years pushed study of the origins of bipedalism back from the Pliocene into the early Miocene. It also challenged the commonly held concept that the acquisition of habitual bipedalism is an appropriate marker of the separation of the hominins from the panins (bonobos and chimpanzees), a separation that is estimated to have occurred only 5-8 million years ago. It pushed the context of bipedal origins back into the forest canopy from the ground (Senut 2011) where it had spent some considerable time as a result of the knuckle-walking hypothesis._* *_[...]_* *_Not only did they find clear evidence that modes of knuckle-walking in Pan and Gorilla were fundamentally different (Figure 3), they also found what had been claimed to be knucklewalking adaptations in the carpal morphology of a range of non-knuckle-walking monkeys. Of course it is theoretically possible that knuckle-walking did evolve only once in the common ancestor of the African ape and human clade and that these differences evolved after the Gorilla and Pan lineages split (Kivell & Schmitt 2009). The broad consensus that there is a clear lack of any convincing fossil evidence for knuckle-walking in crown hominoids or early hominins, however, would render it unlikely._* *_[...]_* *_Despite the longevity of the paradigm that derived human bipedalism from chimpanzeelike knuckle-walking, we conclude that the arboreal origin of bipedalism is now overwhelmingly supported by the fossil, biomechanical and ecological evidence. The 50-year reign of the knuckle-walking paradigm must be declared over.»_*
@@nmarbletoe8210: You're welcome. Be sure to make fun of the next person you see with a t-shirt depicting a knuckle-walking chimpanzee progressing to an upright man.
This was so obviously the correct answer, that I got a ramidis tattoo as soon as I turned 18. It never made sense that we transitioned to upright posture on the ground.
Lovely stuff as always! Also, Henry the VIII was a great choice to represent humans ... Quite a specimen! Those calves ... That patchy beard ... That double chin ... That's a human right there!
AFAIK it was established years and years ago that the last common ancestor wasn't a knuckle walker, and that knucklewalking was a development happening after the split. You could also think of knuckle walking and bipedalism as two different evolutionary solutions to the problem of transforming from a primarily arboreal life to a life dominated by ground locomotion. When one method is first established it isn't that easy, in evolutionary terms, to change to another. If knuckle walking was in our ancestry there's no certainty that there would ever be a strong enough evolutionary pressure to change to bipedalism.
I wrote my MPhil dissertation on this topic last year and came to the same conclusion. I also came up with an explanation for why knuckle-walking evolved independently in our closest living relatives. If anyone wants to read it, let me know! (Especially if your name is Stefan and you have a blue shirt? It’s really interesting, I promise!)
@@ewetn1 It sort of evolved 3 times if you include orangutans, but the short answer is bipedal European common ancestor. Climatic changes forced it south into Africa during Green Sahara periods, where some found patches of remaining rainforest and adapted to vertical climbing, and others found nothing but ever-expanding savannah and evolved into us. Just my theory though. It also explains our monogamy, altruism, and ultimately big brains.
@@kimshaw-williams Our early ancestors almost certainly ate both plants and meat and spent a lot of time in the water. Modern savannah chimpanzees do, and they live in a very similar environment to our ape-like ancestors.
When you watch gibbon move around on the ground, and you ask yourself which direction would it go to become more efficient at ground locomotion, you can really imagine it going either way. They walk around on their hind legs a lot, holding their silly-long arms up. :-) And they _also_ occasionally plant their hands on the ground in front of them. One wonders, bio-mechanically-speaking, what small differences very early on would have led to a knuckle-walking vs bipedal divergence.
This is just going to be my interpretation of things, even though I do not focus on it. We have known about S. tchadensis for a while though, most of the people in my paleoanthropology courses have argued it is out common ancestor with chimps, or at least close to it. I agree that it is likely that ancestor. The foramen magnum does suggest some bipedal locomotion, but to my knowlege it is still being argued as to whether or not it was a habitual biped. We don't really have enough evidence yet. The paper mentioned here is certainly interesting and I look forward to reading it as the legs would give us a better idea. Now, if I remember right (I don't actually have a bonobo skull and can't find a great photo) they seem to have a foramen magnum closer to ours than chimps do. Theirs is ever slightly more forward and similar to S. tchadensis. That would make it absolutely a facultative biped, but not fully habitual. I would imagine they favored bipedalism and in trees WOULD have been upright most of the time balancing on branches. It would make sence that if that was our last common ancestor, it broke off into one group who further specialized at jungle movement by reverting more towards strictly facultative bipedalism, and another group who further specialized into our line of habitual bipedalism.
To informal students of primate evolution such as myself, this is a fascinating video. To me the most potentially interesting point in the video is the journal quote "During the Miocene epoch, as many as 100 species of apes roamed throughout the Old World" ! (my exclamation) Sounds like this level of species radiation in the middle to late Miocene was a true evolutionary laboratory where everything gets thrown at the wall to see what sticks. Indeed, this is a very different narrative of where humanity came from. BTW, those old, stereotyped images of human ascendency tell us more about human prejudice and arrogance than they do about how well the people who used them understood the process. They are barely one step removed from The Great Chain of Being and considering man The Crown of Creation. They are repugnant to me and their continuation in popular culture only fosters mistaken thinking. richard -- "The power of accurate observation is commonly called cynicism by those who have not got it." - George Bernard Shaw (through Inspector Javert)
I remember a book I did a show-and-tell on, the subject was the DNA changes in ape-man to man-ape transition. There are so many reasons to believe the classic image of knuckle walking hominids is wrong, but we can't be sure. I have hope we will discover our true origins but this means we're no different from animals and this information might forever need to be shielded from most fragile minded people who wouldn't be able to cope with the idea of just being an animal. (ye those people exist sadly enough)
"The Last Common Ancestor" for those presently alive is a dynamic attribute, irrespective of new discoveries. It's *inherently* dynamic. For extinct branches, yeah should be fixed.
My gut reaction to evolution around knuckle walkers (now that the topic came up) is that it would not really make sense for hands doing double duty as front feet without hands already having existed without this duality. And thus that hands having evolved would likely not evolve to knuckle walking and then back to not being for much walking. This fits with tree-dwelling ancestors evolving good hands, and some of them descending to the ground, and walking around on 4 limbs, while others instead became better at bipedal locomotion.
@@dillpickle8015 I find it hard to believe that someone is so ignorant to think that it was even a relevant thing to say. "Established scientific theories have withstood rigorous scrutiny and embody scientific knowledge."
Johnnie Hougaard Nielsen why is it hard to believe when it was an actual event that happened and you witnessed? Guess that falls in line with the mental process of not wanting to face reality, which births avoidance, denial, frustration and delusion. Yeah, other people’s experiences and experiments are pivotal to understanding the past, present, and future, but just a word of advice, try everything in life for yourself, on both sides, before forming your truth on it.
If you’ve developed big arms and hands for tree-dwelling and you find yourself having to walk on the ground, you would be able to balance better on four limbs and you would be able to move faster. Hominids likely became more terrestrial while other apes became more arboreal (while we were still all in the woods) to avoid competition. The trade-off was that bipedal locomotion was no longer practical. I don’t really have any further evidence for this theory, but it fits with the existing evidence, so I will choose to believe and teach it until proven otherwise.
I just read his back a couple weeks ago. I really enjoyed this point on knuckle walking. I found the second half of the book as being the type of pedantic stuff I got from the anatomists and physiologists in med school. I felt like it was filler, but the first half more than made up for it
And this way, science is leading us to refine more and more the knowledge of the world. The orthogenetic model is clearly badly outdated and the signal of what happened is so strong that even with fragments of [once] biological material we manage to accurately predict, correlate and articulate this fascinating story. This video is specially well-crafted and of highly educational value.
I can see knuckle walking coming up in gorillas simply because of their size and weight, as the only solution to both terrestrial and arboreal locomotion. Knuckle walking would be the only way to support and distribute that much mass while still allowing the kind of joint and foot structure that would allow good climbing skills. But if chimps are not much larger or heavier than fractionally bipedal ancestors, that explanation would not hold. In the case of chimps perhaps modern chimps are much better climbers than our last common ancestor, who might have been a jack of all trades but master of none, so to speak. From that ancestor we decided to double down on walking and became us (eventually) and other populations decided to double down on climbing and became chimps and bonobos. Interesting question however you slice it.
It’s all about the environment: jungle, mosaic woodland, etc. The structure of the trees our ancestors were in influenced our arboreal locomotion. V different from the trees that other great ape ancestors evolved in.
Super interesting. We had that Time-Life book in the house when I was growing up as well as many others they published on ancient history, natural history, archeology & anthropology (long before wikipedia & the internet we had these things called encycopedias.) It's been fascinating to see how much the natural sciences have grown & changed & advanced technologically. Are these new discoveries adding to the Out Of Africa theory or are they starting to cast doubt on its validity?
This hypothesis is popular these days, and I see the reasons why. But I'm still skeptical. Knuckle-walking is very unique among primates; you see it in gorillas, chimpanzees and bonobos only. And these happen to be our closest relatives. So parsimony suggests a knuckle-walking common ancestor (if gorillas and chimps were more closely related this would not be the conclusion). Darwin was among the first to point out the anatomical similarities between humans and these specific apes, and thus proposed that our ancestry was in Africa (he's given too little credit for this specific part). That the anatomy of the gorilla is more "columnar" is not surprising; it's heavier than chimps. Given that Ardipithecus was already bipedal I wouldn't expect there to be much evidence in its wrists.
I think the focus on knuckle walking-as opposed to quadrupedalism in general-is a bit of a diversion: many primates use all four limbs to bear weight, walk and run. So, while knuckle walking is rare (it has been observed in some baboons, as well), quadrupedalism is anything but. To me the question isn't why did chimps/apes evolve to knuckle walk (although they question of whether they did so independently/separately obviously has implications for the human evolution). Rather, the key question for me in this area is why did the ancestors of gorillas and chimps evolve to rely on terrestrial quadrupedalism instead of terrestrial bipedalism.
@@Grey_Ocean2023knuckle-walking might be caused by specialisation in brachiation in the first place. No other species of extant apes (aside from us) is as terrestrial as gorillas and chimps (and bonobos). But the high level of terrestriality is likely to be secondary to brachiation in the trees. Both, the palms and feet of gorillas and chimps are highly specialised. On the other hand, those of Ardi were quite primitive, in many respects more similar to Proconsul and some other stem apes. If the LCA of hominins and chimps was a specialised brachiator and knuckle-walker this would require evolutionary reversion in Ardi, which is also not very parsimonious. When it comes to your question - why terrestrial quadrupedalism instead of bipedalism in gorillas and chimps? Well, monkeys (sensu simians) are generally quadrupedal, so this seems to be the most obvious posture. What's more the adaptations to brachiation (as well as to vertical climbing), observable in gorillas and chimps would require far more changes to adapt to terrestrial bipedalism than to quadrupedalism. The primitive condition represented for example by Proconsul is a way better starting point. Ardi and presumably the LCA with chimps differed from Proconsul by their broad chest and position of scapulas. Those features are traditionally interpreted as brachiation connected. The original descriptors of Ardi suggest those served a more general increase in arm mobility, being good preadaptation to brachiation, but not being directly related to it. I guess our LCA with chimps never went into brachiation as far as chimps did. But this thesis of course would require a parallel evolution between gorillas and chimpanzees. I only meant to show this hypothesis is plausible. On the other hand, I can buy separate knuckle-walking evolution, but what about brachiation - more or less expressed in all living apes aside from us? Are our 'primitve' features (more Proconsul-like) really primitive, or are those reversals? Those features include manus and foot construction. So this is not like that I have no doubts about the hypothesis.
@@StefanMilo Absolutely, and not just hominin fossils; imagine if we find early chimp-ancestors that were NOT knuckle-walkers for instance, that should add complexity to the overall picture (and make the case for independent evolution of knuckle walking).
The Stefan Syllogism, as formulated by numerous independent scholars: 1. A characteristic trait of modern humans is storytelling. 2. Stefan is a great storyteller. 3. Therefore, Stefan is a human. This wild hypothesis remains to be tested.
just wanted to come back and watch this amazing video again after reading about Anadoluvius turkae. the level of research and the amount of effort you put into these videos is greatly appreciated
Funny - a quick review of comments reveals that I'm not the only child that was fascinated by that Time LIfe Evolution book back in the early '60s. For a hoot, check out another book from that era (1959) "All About Prehistoric Cave Men" - another incredibly fascinating book for a child back then. I'm pretty sure all those theories contained within have been de-bunked by now....
@@alexmurray4561 Really there are just to many problems with it let’s start we came from fish supposedly so there would be an evolution of the fish going through changes all the way to man and there would then be a lot of fossil records it would be impossible for there not to be any showing us the changes correct. The problem is there are none. So just right here we prove man came from man we find a lot of fossil records from man. I can give you a years worth of evidence but if it’s your mind already set your going to continue with this bs evolution myth
Firstly, the lack of a fossil record would not prove that man can from man, that would only prove that there is no fossil record supporting it, there is more than enough evidence from DNA to support evolution. Secondly, ‘the problem is there are none’ this is wrong, the fossil record supports the evolution of Placodermi (jawed fish) into Coelacanth (bony fish) into Panderichthys (fish with the beginnings of 4 limbs, a two lobed brain, and spiracle eyes) into Tikalliik and Acanthostega (more distinct limbs, a rib cage and lungs) into Ichthyostega (no scales, eardrums, stronger bones, the beginnings of fingers, tear glands for wet eyes out of water) into Pederpes (shell-less eggs, an early nose, tongue, salivary glands, thyroid glands, the three-chambered human heart, bladders and most importantly 5-fingered hands) into Hylonomus (first reptile, keratin used for claws (the material in hair and fingernails) sharp teeth, and no gills, adrenal glands, dry scaled skin, more advanced brain system) into Therapsids (no scales, no gastralia, probably warm-blooded, secondary palate (eating and breathing at the same time like we can) and advanced jaws) into cynodonts (advanced lungs, advanced rib cages, lymphatic systems and immune systems, orbital bones and mammalian jaws) into eucynodontia (first mammals, devolved from 4 colour to 2 colour vision, advanced smell system, neocortex In the brain, prostate gland, advanced eardrums, sweat glands and fur, four-chambered hearts (exactly like humans), peni ses, fully separated teeth, SRY gene (differences between sexes)) into Therians (nipples, anal and genitalia, advanced hearing and most importantly live birth (no eggs), Euarchonta (only two nipples (like humans) and opposed fingers) Early primates (expanded brain with 4 pairs of lobes) specialised metabolism lost the ability to produce Vitamin C (like us), claws turned into nails) into Simians (hunted in the day, no claws, sinuses, and a menstrual cycle) into Catarrhini (three colour vision (like us), tooth enamel, shorter arms (like us), no tail, and bigger brain) into Homindae (shorter noses, wide flat ribcage, strong spines, shoulder blades) into Hominini (voice box, larger brain and flexible wrists and elbows) into Australopithecus (walks on two legs, better pregnancy, ate meat as well as plants) and so on to the Homo genus.
@@alexmurray4561 you say all this but we find zero fossils to prove it but we find a lot of man fossils that didn’t evolve it’s a regular fossil it doesn’t take a genius to know if you don’t have physical proof don’t push your narrative on me
Fascinating revelations and implications in this video - bipedalism vs knuckle-walking. Stefan, I must commend you on te overall composition and execution of this episode. It was truly a "professional" product. Camera angles, lighting, audio quality, and especially the balance between interview, discussion, and musical elements. Right on!
Love the bipedal gibbon! That makes so much sense. So as the forests were turning into savannas three lineages of apes were experimenting with how to move between the stands of trees most efficiently. One did it on 2 legs and two did it on all fours, and they were all successful because they all still exist today.
Of course more fossils will change our ideas, just as we now look back on the book from 1965 with different opinions. But I do think this theory 'has legs' (badum tsss) What do you all think?
Huge thanks to Prof. DeSilva for his help! Check out his brilliant book here: www.amazon.com/dp/0062938495/ref=cm_sw_em_r_mt_dp_MMN6K0SR2C9A98CCJ7BG
There may be a typo in the video title
@@sungodra1226 maybe ;)
@@CubeFlow_46 *insert rock eyebrow raise*
@@sungodra1226 lmao
When are you making the next video?!
Omg. I was born in '62, and my mom brought me that Time-Life book on human evolution. Even though I was too young and the text of the book was beyond me, I was fascinated by the idea of evolution. I took the book with me the first time I went to summer camp, instead of a stuffed toy or security blanket.
That’s brilliant! They’re cheap to buy, plenty of copies. Get one for your book shelf
I have the whole series of those books sitting the shelf right now in Australia 🇦🇺
@@StefanMilo Your videos are quite well done, brother, but I would not buy them because they are so directly derived from what I call the 'standard evolutionary textbook'' (SET) paradigm...which holds that 3.4 mya Lucy was our Pliocene ancestor, even after Ardi turned up.. it is a belief held only by the American Chicago-based paleo-theorists, not English people like the Leakeys, or the French paleo-anthropologists. I wish you would have a decent photographically based look at the 6 to 5.7 My footprints found on the seashore of Crete by Gierlinski et al 2017 (it took them 8 years to get their paper published), and cover Attenborough's treatment of the aquatic wading theory of how we became obligate bipeds. We did NOT come down out of the trees, no, our descendant lineages of orangutans, gorillas and chimps moved into the trees and became much more arboreal, frugivorous apes. It is actually far more logical to believe that some wading, sedgivorous australopiths became chimpanzees, and the larger paranthropus sedgivores became gorillas. That is why we have never found any old chimpanzee and gorilla fossils.
I just noticed that my phone spelled "bought," "brought" in my comment above!
Me Too...at 5 yrs old (1968), I read it from cover to cover for the first time.
There seems to be a rule of human history, that "Everything Was Earlier" (than the classical account). The more we discover, the earlier everything gets: writing, domesticating animals, understanding the stars...
I think part of that is because there's this bias that early humans were dumb. They weren't. They're just as smart and observant as we are today. We just have a wealth of knowledge at our fingertips that they didn't.
How old is writing?
@@FlauFly At least, 6000 years. But it could easily 10.000, or more...
I mean the simple fact is that you rarely discover the absolute first of something just by statistical probability.
it’s not really a rule, and i think a distinction should be made. people like to signify the oldest stuff *known.* no one is saying we’ve found the oldest writing, but there is writing we have that is the oldest to us
This makes a very good point. Knuckle walking is not an obvious form of locomotion and would be more likely to be a specialist adaptation for a larger primate. The example of the gibbon shows very well how our distant ancestors may have walked and then as those which eventually became hominids chose bipedalism, others adopted a different method.
That is actually a very poor point. There is clear evidence in GENESIS that man has always walked on two arms! This directly refutes this video.
Hahahahahaha!
Shoutout to those who were here when the title read We We Wrong
yessir
We we wrong gang 😎
Made it in time
We We Wrong Gang
Woohoo…still there
The possibility that knuckle walking evolved 2 separate times was especially interesting to me. I love the content you are putting out. Thank you, Stefan!
It makes sense, when you think about it. Quadrapeds are more stable than bipeds. You'd only expect bipedalism to stick around if there was a good reason for it (maybe like increasingly heavy dependence on tool use).
They both live in similar enviroments so it isnt that unreasonable
If I think of it just as a method of locomotion, it reminds me of flight evolving differently in bats than in birds.
I would love to know more about this knuckle walking theory
"Evolution hasn't been observed while it's happening".
So it fails the scientific method.
“Why did nuckle walking evolve?” Damn, now I am interested. A follow up on this case would be awesome. Great stuff!
It's probably the link between palm walking and upright walking. Knuckle walking raises you up a little bit higher than palm walking.
@@SCORP1ONF1RE More robust posture is likely a reason as well.
It is probably a vast array of causes. The natural habitat for both apes is a heavily forested, as well as having small shrubbery. What do humans do when we're going through a low tree line? We squat lower to avoid from getting our faces hit by branches. The amount of times you squat low rises, might as well always walk in a lower posture permanently. If climbing, you want a stronger base of 4 limbs on the floor but be ready to grab onto something quickly. In that case you might adobt walking on knuckles instead of palms as your hands are in a much more natural position to grasp at trees, rocks, etc. Just my 2 cents.
@@maymunity7942 My thoughts as well.
I thought bipedalism evolved back with gibbons (lesser apes), but to avoid competition with bipedal apes the asian apes went arborea and the african apes adopted knuckle walking?
When I was a kid, before I started first grade, my neighbor who had just returned from the Vietnam war handed me that book one summer afternoon and told me I could keep it and that I should read it someday when I am able to read. That was the summer before starting Catholic school, and I eventually took that book in for show & tell. I got sent home, with a beating from a horrible Nun who had a beef with Darwin. And that solidified my love of that book and everything in it.
My disillusionment with Catholicism started in the first grade. I had recently lost my dog and when we were being taught about heaven I asked the nun if I would see my dog again if I went to heaven. She said "no, dogs do not go to heaven". Not sure I was as interested in the whole thing after that.
Especially ridiculous since the catholic church has officially respected Darwin and the theory of evolution since like 1950
@@robertspies4695 Seriously, what a horrible thing to say to a child. And who wants to go to a place where there are no dogs?
@@JackMyersPhotography Not me. I could be become a believer again despite my life in science if I could have all my dogs back in heaven.
It's funny because I remember some creationists (both Christian and Muslim) who said apes evolved from sinful degenerate humans, so they should love this theory!
I dont know why, but i'm blown away by the notion that there were apes essentially all over Europe. I had just just always assumed apes = jungles = equator = Africa.
Apes are also in Asia. There are lots of jungles outside of Africa.
Apes have to be around fruit trees And away from humans to survive and grow.. they have had millions of years to grow in this Darwin theory and they never have proportionately they are stuck on that little piece of land that God put them on as primates he did not put them in the North Pole with polar bears or in the desert with camels supposed to evolution theory is false and fake on the climatic environmental theory alone
I was the same. Then I searched up climate during the Miocene and it all made sense.
Later, when homo erectus left Africa and went to what’s now Georgia 1.8 million years ago (and to China even earlier), Georgia had a Mediterranean climate.
@@aleanbh3808 old HEBREW documents Suggested Africa was batren of western mankind until Hebrews punished a wrongdoer by banishing him to the humanless African jungles, where he mated with now extinct 6 foot wallkings apes, this hints at Africans being the missing or lost tribe descendants of the original tribe member banished to humanless documented jungles south of the Middle East,, Over centuries Evolution of this inbreeding has populated the Continent,. or are we to Believe Africans here as long as non Africans and they wouldn't civilize as population to the north and or other continents & people's?
Bananas don't grow in Europe.
Actually, this has been the theory of a French paleoanthropologist for at least 10 years now: Pascal Picq. He wrote a few books about it. His theory is that the last common ancestor of human/chimps lived in Eurasia, which would account for the existence of orang-outangs and gibbons. When the forests started to recede in Europe, some of these primates moved back to Africa and other to Asia. There was also a documentary on this topics on Arte, based on the theories of Madelaine Böhme in 2020.
there are some indications there were fossils found of apes in Eurasia, but those was far more basale than the common ancesters of the chimps and humans and in fact far more primitive the the whole ape line, including the oldest African ape Ekembo. They are very hard to distinguish from monkeys.
Found and skimmed some old history books from the 50s and 60s in the past. The differences a few decades make can be surprising. Makes me laugh when people say, "the science is settled". It's regularly changed and adjusted.
Certain things are settled, certain things are not. Common ancestry is not just settled, it’s a fact.
It has been changing and adjusting since the 19th century! Nothing will be settled for a long time!
Well the Earth adjusted from being flat to being round but now I think it is shaped more like an egg due to the ocean tides.
Stefan, I'd known that the famous art at the beginning of the video had fallen into disfavor among the paleo cognoscenti, but this video is the first to fully explain to me why that is so. Thank you.
Well one thing that I didn’t mention is that many blame this image for the misconception “if we evolved from apes, then why are there still apes”.
They blame this linear representation of evolution for that misconception because it doesn’t accurately portray the fact that we didn’t evolve from chimps, but we share a common ancestor.
Also it implies a single linear “progression” from ape to man, rather than the highly branched tree that has now emerged.
@@StefanMilo all people has to do is read Darwin's books or read alfred r. Wallace (the pete best of biology). But they won't read them, they just follow. Darwin didn't replace al but the impact and news coverage was the same. Darwin had his evolutionary theory first but took forever to get the book going, i believe if alfred hadn't contacted Darwin, Darwin may have died before he published origins. I wish you could do a video explaining a scientific theory, the non evolutionary believers always say " it's a theory so it's not true". Please explain why it's called theory. I get tired of trying to explain to people posting that, I'm glad you covered " we didn't evolve from apes". They would know if they just read the books. Anyhoo, very good videos. 👍
@@adamrodaway9116 It's neither progressive, nor linear. The figure excludes all the lineages that ended extinct since our split from chimpanzee's ancestors
That book,"Early Man",was one of the joys of my life around age 10 to 17. Stunning artwork in there. The whole 'Time/Life' series was awesome. My concurrent budding interest in Comparative Religion made for a vibrant,if confusing, intellectual life. My youthful passion for dinosaurs and anthropology makes me fully appreciate what we've learned in just a few decades. Questions remain,but so many have been answered. This is a great channel!
Humans and dinosaurs lived together at least until the worldwide flood, and perhaps even after.
@@earlysdadinosaurs is feak
The ape-men were not human ancestors. They were the result of human-ape hybridization, probably in Genesis 6 : 12.
The DNA of Neanderthals and Denisovans was 15-16ths human and 1-16th chimpanzee.
I recognized that book instantly and then had the jarring experience of it being called a textbook? I LOVED the time/life books, the Universe and Mathematics were my favorties.
We We Wrong baby, Stefan's putting out such fire content that it has began to melt his brain! :D
Lol woops my bad
@@StefanMilo Don't worry man! And thanks for the awesome video. I have learned so much from your content and also challenged a few things I previously believed :).
Every time you’ve even pondered calling a modern black person a n*gg*r, you were insulting your ancestors. Just a thought, my friend.
@@ryanmillichap8327 yeah, except its not true.
He’s starting a movement “we we”
Your videos were always among the best, but you've transcended that over the last year. These are in a league of their own and I'm so thankful you're making this content.
My next video briefly mentions this same thing as it is going to be a dissection of a recent "out of africa debunk" video that brought up Ardi and Lucy- I'll have to mention this video for further learning!
Nice plug
Damn it, you got my attention.
1:35 Wow, straight up racism. But then, Evolution has been based on racism ever since Darwin's famous book - "Favored Races". Time to return to God.
Zeke,I hope you’re in agreement with debunking the “out-of-africa” theory. The 1990s study that blew the theory up was intentionally misinterpreted, twisting the researchers’ words/research. It was done by the media et al to give the “out-of-africa” theory legitimacy, in order to make the study fit in with the Afro-Centric movement that was being pushed.
The researchers themselves have written about it, and what their research/paper _ACTUALLY_ says, but the damage had already been done.
Anyways, I agree with Red Riding Hood here - nice plug lol. At least it’s good to see that your two video titles reflect you know humans origins consisted of multiple species (but only the brave scientists will admit that there are still more differences in human groups today than what is needed as requirements to prove an animal group is a sub-species).
@@anti-ethniccleansing465 you’ll be very disappointed. :)
the quality of your videos has been amazing recently, this was straight up a mini documentary. really well done stefan!
Stefan, you are an extraordinary science communicator! Your ability to handle both complex scientific topics and to humanize even our most distant ancestors is singular. Love what you are doing and am excited every time I get a notification that a new video is up.
Edit: The quality of your videos has improved so much in the last year or so. Have you approached Nebula? Hell, I think your recent videos are matching the quality you see on Curiosity Stream. Would love to see you on additional platforms.
But please keep giving us free access youtube videos.
@@Where_is_Waldo Most Nebula creators still do UA-cam (to the best of my knowledge) and either release early on Nebula or include less algorithmically successful pieces exclusively on Nebula. But Nebula and Curiosity Stream are like $13.00 (both) yearly! It's the best value paid media out there.
Wish I would have had professors like him, who really stir up a young mind’s curiosity.
Evolution is a fairy tale for grown-ups.
@@earlysda Thanks for defining projection.
We we love this channel.
oui j'aime aussi beaucoup
"Evolution hasn't been observed while it's happening."
What l find fascinating and also incredibly frustrating is when a certain group of people declares that scientists are arrogant and pretend to have all the answers when the exact opposite is true. Just because science and evidence disagrees with your worldview doesn’t mean science is wrong or presumptuous. It means you have to be humble and revise all your premises. Unfortunately, that seems to be a step too far for many people.
I loved your videos from the start, but I have to say you keep improving them by leaps and bounds every time. This was fascinating and brilliant, and I have to say Prof DeSilva is an excellent science communicator, too!
Yeah, but I miss the spoon...
Incredibly interesting! The thirst for the true history of things is sometimes a curse. All we can do is take our best guess on what little we are given. Thanks so much for a very entertaining video.
But think about it... Just in my lifetime we've gone from this march of progress idea to this theory that we were already somewhat bipedal. We've discovered so much and developed new technology at such a fast rate in a relatively short amount of time. Who knows what we'll find out next?
I am a 1961 vintage human, this book blew my mind at around 1967. A bit dated but I still have it and a few more from that series.
I discovered science
Love your videos Stefan. I always rewatch a few older videos after you upload - I love the way you tell a story and produce your videos. A true gem on UA-cam.
I find the hand bones interesting, because I broke my hand recently. They said my hand bones were significantly thicker than most people they had seen. (Citation below)
Probably not surprising, since I climb trees for living and have for quite some time now.
Edit: to clarify one issue in physical anthropology is often differences that often are assumed to be genetic, might be developmental
“Prior exercise significantly correlated to cortical thickness (r = 0.13; p < 0.002) and periosteal circumference (r = 0.18; p < 0.005). Cadets in the highest exercise group had 5.8% higher cortical thickness compared to those in the lowest exercise group (p < 0.04; Figure 1).”
Determinants of bone mass and bone size in a large cohort of physically active young adult men
Nutrition and Metabolism 3, article 14
JA Ruffing et al
Feb 15
I was going to say something similar. My mom was born with one leg substantially longer than the other. As a result her big toe on the short leg side is three times the size of the long leg side. This is because she is always supporting that side with only her big toe while being flat foot on the other.
You climb trees for a living? Dude, that's awesome. Did your bigger hand bones make it easier for you or did you develop them from climbing.?
@@frankconley7630 well I don’t have any real data to back it up. But, my hands and certainly my knuckles seem to have gotten significantly thicker, while the rest of me hasn’t.
That said people in my industry tend to get retired from the field due to shoulder, and elbow overuse injuries. So while we might be able to adapt to some degree, we obviously are limited genetically
How did you break your hand with really thick bones?
@@mushmush4980 pretty good sized chunk(1000ish pounds) of Doug fir rolled across it.
Ok, now I'm really curious about all the advantages of knuckle walking since it may have appeared two times independently :)
I heard it can support higher weights and possibly allows for stronger arms wich would be useful in interspecific competition i guess ,
But to be honest i don't know
Stronger arms would also support a better ability to climb.
We have problems giving birth by being upright, we may have stayed/ been chased to stay on the plains .
Allows faster running.
@@AK-ks1kq It's the advent of using fire for cooking that made our brains larger, not walking on two feet.
Honestly this and crocodiles having warm blooded metabolisms are two of the biggest paradime shifts in the field of paleontology :
They basically flip the whole idea of what an advanced animal should look like , we assumed us and birds where evolved and advanced because of our bipedalism and higher metabolism so obiusly chimps and crocs are the lower step the less advanced creatures ,
Then we realize crocodiles where also warmblooded long ago and they became cold blooded because they didn't start as ambush hunters ,
And chimps evolved knucle walking while we where on our march around the world making turtles extinct ,
So yeah there is really no up or down in classifying species only left and right , r and K strategists ,
High metabolism or low metabolism ,
I type survival curve or
III type survival curve
Neither one is superior to the other , both are better in certain situations
Very astute, well done.
Evolution is a fairy tale.
@@earlysda Tell that to Australian aboriginals..
@@botezsimp5808 Botez - WOW! Your comment is the worst racist comment I've seen on the net in quite a while.
@@earlysda OK troll bot. 👌
Loved that 1965 Time-Life book. It was one of the things that set me on the path to understanding human evolution, and getting a degree in Anthropology. I now have a pdf copy of the book.
This channel really is one of the hidden treasures of UA-cam.
That makes sense. I've always despised recreations of our ancestors showing them as clumsy, hunched over bipedalists. They were as upright and graceful at it as we are today.
Well, somebody wasn't.
Presumably the first bipedalist wasn't entirely adapted to that method of walking.
13:30 if you spend a bit of time in the forest you will realize that knuckle walking is an adaptation to aid in getting through thick brush.
Standing upright is very difficult for getting through the tangled branches that often spread out upwards, but are more sparse down low.
Correct ... Then if you go into the open ~plains of an area, up-right walking is as good or better than knuckle walking plus gives much better vision of your area.
I still have that book on Early Man from 1965. It was my favorite book my collection of the Life Nature Library books. I studied that thing over and over. I love that the video opened with it.
I loved this Time-Life science series that included "Early Man." I read them all religiously when I was 11 and was particularly fond of "Early Man", "the Universe" and "the Mind". In a different time when knowledge was cloistered, it was an introduction and a keyhole into a dozen different scientific domains.
I grew up with those Time Life books; I remember the one called The Mind in particular. I don’t think we had them at home but we would often get them from the library. We were Catholics but my parents had no quarrel with anything to do with science. We kids had a subscription to a children’s version of the Time Life series; they were wonderful books too. All kinds of topics, from dinosaurs to shipwrecks to one on spiders with huge closeup pictures that we would dare each other to look at. I kind of wish we’d kept them all.
@@KathyPrendergast-cu5ci A lady at my Mom's church gave her many boxes filled with this series of books. For an average curious 10/11 year old child, it was a solid introduction to life sciences, physics, astronomy, social sciences, archaeology, the history of math and philosophy in broad strokes.
I can't explain it, but seeing Dr. DeSilva holding Sahelanthropus makes my chest ache. I don't know how to describe it. Curiosity? A connection? Some weird, misplaced sense of nostalgia? I can't fully put it into words, but I think it feels... right.
I also get that weird sort of nostalgic feeling when studying ancient skulls. It feels like recognition.
Good video. The idea that knuckle walking is the new adaptation seems reasonable. What I've noticed when I've been on crutches, when I use my hiking poles, or when I climb up rocks or a stair, engaging four 'limb' movement is faster, more secure, more versatile. In Japan those really steep traditional home stairs? If there's anything at all I can grab on to with my hands (and I only need 2-3 points to go up a full story) then I'm rapid (I think it's the fastest way for a human to climb. Ladders and regular stairs are slow in comparison) and it's secure; same going down. So knuckle walking has a lot going for it, unless.... you live on a open savanna for a million or 150,000 years or need to cross distances on reasonably flat ground, and somewhere along the way you start using a lot of hand tools.
Great points to add on to this video
Using knuckle-walker as a slur now
"There are no other mammals, in the forest today, walking around on two legs, like me."
Sasquatch would like a word with the producer, please.
Except it doesn't exist
I just came to this channel and I'm so incredibly in love with it. The sense of humor, the content, the video style. Ugh I'm subbing!!
I'm so happy I found this channel!
I’ve been fascinated by ancient hominids etc since reading Richard Leakeys book Origins.. he described finding “The Turkana Boy “ about 2 million years old and postulated how he might’ve lived and more importantly to me, died. I was hooked, and hence why I’m delighted to have found this series… nice one ☝️🏴
A theory suggests bipedalism evolved from knuckle walking because hominids had to start rising upright to look over tall grass.
What if instead knuckle walking evolved because of the environments the knuckle walkers found themselves in - densely packed which would've made for constant ducking if bipedal, and walking on four limbs gave them more balance on tree branches? If the forests became denser and denser maybe their ancestors went from crouching all the time to knuckle walking.
And it grants more stability for carrying infants on their backs.
Knuckle walking would still allow them to use their hands for minor tool manipulation and tree climbing, rather than their hands simply shrinking to be more paw-like.
It's so fascinating to ask
Great video. Bipedalism is rare in mammals, but so is knuckle walking. What would the selective presssures be to evolve knuckle walking? Maybe it helped chimps become more arboreal, but just how arboreal are gorillas? The male gorilla is huge, and I don't know how arboreal they actually are.
Last year I heard that the ancestors of chimpanzees had hands more like our hands. It is good to see more openness to data rather than sticking to a narrative based largely on supposition.
@@kmadge9820 Remember gorillas split off from the common ancestor of humans and chimps. So either the similarities between chimps and gorillas is the result of common ancetry or convergent evolion. If it is convergent evolution, what were the selective forces driving this? If these similarities are due to an arboreal lifestyle, then what drove gorillas to become to large?
@@davidwood8730 I didn't mention gorillas. I pointed out that the common ancestor had hands like ours, not chimps, and chimpanzees' hands are a refinement consequent on arboreal life. Most likely reason for chimpanzees being relatively small and light is that it's advantageous in climbing tree tops and escaping predators. Gorillas live mainly on the ground and their advantage is in fighting predators.
@@kmadge9820 Curious which animals prey on gorillas (Other than humans). And why they benefitted from coming down from the trees, but chimps didn't.
@@GhostScout42 Yes, it doesn't seem likelly our common ancestor was that large. What selective forces caused them to grow and abandon an arboreal lifestyle? They can't have left the trees that long ago because they retain so many arboreal adaptations.
Eventually we will all evolve into crabs.
Larry the lobster approves this message
Amen
Thanks! That's the first paradigm shift I've experienced in a long time. I love it when the universe flips the script on human understanding
It might be unrelated at all, but one of the things that came to my mind as you were discussing feet shape, was leg disorders in babies, where most common is curled in feet (resembling our tree climbing relatives imo) - can/does this tell us anything about our evolution?
Interesting. Developmental disorders in modern humans may follow an evolutionary path.
@@62Cristoforo ya, i know it's hypothesized in embrio, at the same time we human love finding connections ;)
Looking farther at this, i found two different phenomena in babies: first is Toes Curling - which is part of normal development (looks to me like "grasp mom/tree" reflex hh). second is Pediatric Bowlegs, which usually is also considered normal in infancy (and usually fixes itself when infant starts walking and putting upward/standing weight on their legs).
Interesting stuff.
@@MI-wc6nk interestingly enough "swimmer babies" can occur in dogs, cats, and even birds.
Oh baby. Yes please
I enjoy your lighthearted approach to what can be a dry subject.
Good work Mr Stefan
Really outstanding work! Such an interesting subject. Professor DeSilva is such a great speaker!
Dude, we had that Early Man book in our house when I was a kid! Ever since, I've been fascinated by what we (incorrectly!) called "ape men" or "cave men", and wondered what their day was like when they woke up each morning. I knew they were biologically close to us, and that their brains must have been much like ours, but I knew that their bones told of often horribly injured, broken bodies, and incredibly tough lives. That contrast between intellectual consciousness and physical brutality was just mind bending to think about.
I’m thinking that so-called “cavemen” didn’t live in caves. They just liked to explore them and leave art on the walls. Their lifestyle may not have as brutal as you suggest- think of tribes of Native Americans. Some of the early European settlers left their settlements to join those tribes.
Fun fact, The scientific name for Chimpanzees is Pan troglodytes. The word troglodytes literally means "cave dwellers". Guess where no chimpanzee lives
Humans are basically cave apes. We modern humans even build our own 'caves'.
@@darko714 which is exactly why hearths are excavated in caves and the remains of cooked flesh dating back to the, you guessed it, STONE AGE and Cave Men and Cave Women.
God made humans on day 6, and he made them perfect. They were taller, stronger, bigger, and smarter than we are today.
Good thought provoking video. Could be that knuckle walking evolved because of the environment and to relieve back stress. While in the trees apes and chimps undoubtedly developed large upper body strength and mass, long/ longish arms and great pecs. While their lower bodies developed some but just couldn't keep up with their upper halves. So when they got on the ground with all of the underbrush in the forested areas they probably had to crouch and crawl to get to a clear spot and when they stood up they were probably good for short distances but then their upper body mass and weight would put a lot of strain on their lower backs so they would lean forward onto their hands. They heavily relied on their hands and arms for locomotion in the trees they just continued with that when they were on the ground.
Are you implying Chimps skipped leg day? Massive pecs and tiny quads?
@@bbirda1287 This is what led to the new workout routines that would equalize everything.
I recall reading that knuckle-walking was a derived trait that the common ancestor didn't exhibit.
It's so refreshing to watch a well-researched scientific lesson. No ancient aliens, no bizarre theories - just science. Thank you! (Side note: I still have a copy of that Time-Life book!)
Its just as retarded and made up. They literally just dug up some chimpanzee bones and claimed their human with no evidence.
"Evolution hasn't been observed while it's happening.*
That means it is not scientific at all.
@@earlysda You can't "see" an atom but we know it is there. You can't see the wind and yet there it is. Since no one is around for a few million years to observe, we rely on a range of indirect proofs of evolution - bone fragments (and most recently, DNA analysis for a limited group of samples). We don't always know HOW evolutionary changes happened, but it's clear they're real.
@@rgnyc R G, You are years behind the times. Yes, we can see atoms.
.
Evolution has never been observed while it's happening.
.
That means Evolution fails the scientific method.
@@earlysda we have definitely observed accelerated (macro) evolution in a multitude of animals. And what you said isnt true whatsoever, definitionally we cannot observe blackholes or the big bang but via indirect evidence and inference we can gather an understanding of these things. Under your view electrons, black holes, the big bang, gravity and virtual particles arent scientific concepts. We cannot directly observe any of these phenomena but can see their existence through their effect on things around them.
I had that book when I was a child back in the 1960's. Though the evidence we have now makes it clear that much of what was in that book was incorrect, it did get my interest in paleoanthropology going, and at the time, it was right up to date with what the thinking was. It is really amazing to see how far our knowledge has progressed in just in one lifetime. There can be no doubt that there will be further changes to our knowledge, and more fleshing out of the whole picture as time goes on, and I envy the currently young people who will be around to witness it. The world is a fascinating place, and for the curious, ten thousand years would not be enough to learn/see it all, yet on average, we are granted only seventy-five years enjoy it and drink in as much of it as we can. Such a precious gift we have. Do not waste it.
This channel is like Veritasium, but for anthropology
We we wrong the whole time.
The science of paleo is in constant change. Which makes it very exciting as well as very confusing. With many having their own interpretations. It is one of the fields we may never know the full truth about. I found this piece informative. Thank for putting it together.
Awesome vid man!
"Were We Wrong" always strikes me as click-baity when it comes science news story headlines. New data generates new hypotheses or eliminates old ones. That is what the modern scientific process is all about - figuring out how we got things wrong previously.
And yet, that doesn't eliminate the need for channels to bait users into clicking
Excellent, I have been trying to make this same point to students. We didn't evolve from chimpanzees, both chimpanzees and we have been evolving from something different from both of us to arrive at our current forms.
Well put. That is an obvious but often made mistake....I also think we should look at a semi-acquatic, continually wading scenario....forget the trees, most fruit trees had not evolved until the Late Miocene.
I don't think that knuckle-walking is a downward evolution, but merely a different path those species took. Respect the cousins!
I've been saying this for several years now, for many of the exact same reasons. Everyone should read the paper called _The arboreal origins of human bipedalism_ for a better understanding of this. They talk not only about the fossils discussed here, but the fossils of even earlier hominoids, so-called "crown" hominoids that lived with an upright posture in the canopy of the trees as long as 20 million years ago, and which are the ancestors of all living apes.
*_«By the early 2000s the fossil record of the Eurasian and East African Miocene (23-5 million years ago (Ma)) was burgeoning and revealing the body form of early ‘crown’ hominoids ('crown’ hominoids being the direct ancestors of all living apes, including humans). These included fossils of species such as Morotopithecus bishopi (from approximately 18-22 Ma), Pierolapithecus catalaunicus (c. 12 Ma), Hispanopithecus (Dryopithecus) laietanus (c. 10 Ma) and Orrorin tugenensis (6 Ma). These fossils suggested that, contrary to expectations and fossil evidence from Proconsul hesoloni and associated species, the early crown hominoids stood and moved with an orthograde (upright) posture._*
*_[...]_*
*_The fact that orthograde (upright) body postures had been evolving and diversifying in our hominoid ancestry for in excess of 15 million years pushed study of the origins of bipedalism back from the Pliocene into the early Miocene. It also challenged the commonly held concept that the acquisition of habitual bipedalism is an appropriate marker of the separation of the hominins from the panins (bonobos and chimpanzees), a separation that is estimated to have occurred only 5-8 million years ago. It pushed the context of bipedal origins back into the forest canopy from the ground (Senut 2011) where it had spent some considerable time as a result of the knuckle-walking hypothesis._*
*_[...]_*
*_Not only did they find clear evidence that modes of knuckle-walking in Pan and Gorilla were fundamentally different (Figure 3), they also found what had been claimed to be knucklewalking adaptations in the carpal morphology of a range of non-knuckle-walking monkeys. Of course it is theoretically possible that knuckle-walking did evolve only once in the common ancestor of the African ape and human clade and that these differences evolved after the Gorilla and Pan lineages split (Kivell & Schmitt 2009). The broad consensus that there is a clear lack of any convincing fossil evidence for knuckle-walking in crown hominoids or early hominins, however, would render it unlikely._*
*_[...]_*
*_Despite the longevity of the paradigm that derived human bipedalism from chimpanzeelike knuckle-walking, we conclude that the arboreal origin of bipedalism is now overwhelmingly supported by the fossil, biomechanical and ecological evidence. The 50-year reign of the knuckle-walking paradigm must be declared over.»_*
amazing. thanks for the text
@@nmarbletoe8210:
You're welcome. Be sure to make fun of the next person you see with a t-shirt depicting a knuckle-walking chimpanzee progressing to an upright man.
My reaction to new content: ‘Weeee!’ I mean I always enjoy the videos
This was so obviously the correct answer, that I got a ramidis tattoo as soon as I turned 18. It never made sense that we transitioned to upright posture on the ground.
If you spend time looking at the gibbon, the theories surrounding Ardi and our own bipedalism starts making a lot more sense.
Yes, especially Gibbons were the first lineage that split from the common ancestor of all apes.
Lovely stuff as always! Also, Henry the VIII was a great choice to represent humans ... Quite a specimen! Those calves ... That patchy beard ... That double chin ... That's a human right there!
AFAIK it was established years and years ago that the last common ancestor wasn't a knuckle walker, and that knucklewalking was a development happening after the split.
You could also think of knuckle walking and bipedalism as two different evolutionary solutions to the problem of transforming from a primarily arboreal life to a life dominated by ground locomotion. When one method is first established it isn't that easy, in evolutionary terms, to change to another. If knuckle walking was in our ancestry there's no certainty that there would ever be a strong enough evolutionary pressure to change to bipedalism.
I wrote my MPhil dissertation on this topic last year and came to the same conclusion. I also came up with an explanation for why knuckle-walking evolved independently in our closest living relatives. If anyone wants to read it, let me know! (Especially if your name is Stefan and you have a blue shirt? It’s really interesting, I promise!)
Soooo why did knuckle walking evolve twice? Why was it so advantageous to our ancestors?
@@ewetn1 It sort of evolved 3 times if you include orangutans, but the short answer is bipedal European common ancestor. Climatic changes forced it south into Africa during Green Sahara periods, where some found patches of remaining rainforest and adapted to vertical climbing, and others found nothing but ever-expanding savannah and evolved into us. Just my theory though. It also explains our monogamy, altruism, and ultimately big brains.
@@AlexSalikan Kind of heading down the right trail, there, i think....just add omnivory and wading in water all the time
@@kimshaw-williams Our early ancestors almost certainly ate both plants and meat and spent a lot of time in the water. Modern savannah chimpanzees do, and they live in a very similar environment to our ape-like ancestors.
@@AlexSalikanOrangutans are not true knuckle walker
Missing a _"_ *re* _"_ in the title?
Go on though Stefan, love the video.
When you watch gibbon move around on the ground, and you ask yourself which direction would it go to become more efficient at ground locomotion, you can really imagine it going either way. They walk around on their hind legs a lot, holding their silly-long arms up. :-) And they _also_ occasionally plant their hands on the ground in front of them.
One wonders, bio-mechanically-speaking, what small differences very early on would have led to a knuckle-walking vs bipedal divergence.
This is just going to be my interpretation of things, even though I do not focus on it. We have known about S. tchadensis for a while though, most of the people in my paleoanthropology courses have argued it is out common ancestor with chimps, or at least close to it. I agree that it is likely that ancestor. The foramen magnum does suggest some bipedal locomotion, but to my knowlege it is still being argued as to whether or not it was a habitual biped. We don't really have enough evidence yet. The paper mentioned here is certainly interesting and I look forward to reading it as the legs would give us a better idea.
Now, if I remember right (I don't actually have a bonobo skull and can't find a great photo) they seem to have a foramen magnum closer to ours than chimps do. Theirs is ever slightly more forward and similar to S. tchadensis. That would make it absolutely a facultative biped, but not fully habitual. I would imagine they favored bipedalism and in trees WOULD have been upright most of the time balancing on branches. It would make sence that if that was our last common ancestor, it broke off into one group who further specialized at jungle movement by reverting more towards strictly facultative bipedalism, and another group who further specialized into our line of habitual bipedalism.
To informal students of primate evolution such as myself, this is a fascinating video. To me the most potentially interesting point in the video is the journal quote "During the Miocene epoch, as many as 100 species of apes roamed throughout the Old World" ! (my exclamation) Sounds like this level of species radiation in the middle to late Miocene was a true evolutionary laboratory where everything gets thrown at the wall to see what sticks. Indeed, this is a very different narrative of where humanity came from.
BTW, those old, stereotyped images of human ascendency tell us more about human prejudice and arrogance than they do about how well the people who used them understood the process. They are barely one step removed from The Great Chain of Being and considering man The Crown of Creation. They are repugnant to me and their continuation in popular culture only fosters mistaken thinking.
richard
--
"The power of accurate observation is commonly called cynicism by those who have not got it."
- George Bernard Shaw (through Inspector Javert)
I was thinking when I made this video that something about the Miocene would be great, a real planet of the apes. I’ll have to add it to the list.
As an artist that specializes in drawing people I have always known there is no way we descended from the same animal at all
I had that Early Man book when it was new…I guess that makes me Early Man myself 🙁
You’re vintage
Got it new, when I went to college back in 1970! Austrolapithicus Canuckus! Even had the two missing front teeth! 😁 Peace and love from Canada.
I remember a book I did a show-and-tell on, the subject was the DNA changes in ape-man to man-ape transition. There are so many reasons to believe the classic image of knuckle walking hominids is wrong, but we can't be sure.
I have hope we will discover our true origins but this means we're no different from animals and this information might forever need to be shielded from most fragile minded people who wouldn't be able to cope with the idea of just being an animal. (ye those people exist sadly enough)
"The Last Common Ancestor" for those presently alive is a dynamic attribute, irrespective of new discoveries. It's *inherently* dynamic. For extinct branches, yeah should be fixed.
My gut reaction to evolution around knuckle walkers (now that the topic came up) is that it would not really make sense for hands doing double duty as front feet without hands already having existed without this duality. And thus that hands having evolved would likely not evolve to knuckle walking and then back to not being for much walking. This fits with tree-dwelling ancestors evolving good hands, and some of them descending to the ground, and walking around on 4 limbs, while others instead became better at bipedal locomotion.
Or fits even better with evolution being incorrect. It is a theory after all.
@@dillpickle8015 I find it hard to believe that someone is so ignorant to think that it was even a relevant thing to say. "Established scientific theories have withstood rigorous scrutiny and embody scientific knowledge."
Johnnie Hougaard Nielsen why is it hard to believe when it was an actual event that happened and you witnessed? Guess that falls in line with the mental process of not wanting to face reality, which births avoidance, denial, frustration and delusion. Yeah, other people’s experiences and experiments are pivotal to understanding the past, present, and future, but just a word of advice, try everything in life for yourself, on both sides, before forming your truth on it.
Johnnie Hougaard Nielsen and everything is relevant in “say” dilly foose.
If you’ve developed big arms and hands for tree-dwelling and you find yourself having to walk on the ground, you would be able to balance better on four limbs and you would be able to move faster. Hominids likely became more terrestrial while other apes became more arboreal (while we were still all in the woods) to avoid competition. The trade-off was that bipedal locomotion was no longer practical. I don’t really have any further evidence for this theory, but it fits with the existing evidence, so I will choose to believe and teach it until proven otherwise.
I just read his back a couple weeks ago. I really enjoyed this point on knuckle walking. I found the second half of the book as being the type of pedantic stuff I got from the anatomists and physiologists in med school. I felt like it was filler, but the first half more than made up for it
"...there are 𝘣𝘦𝘢𝘳𝘭𝘺 any other animals that walk on two legs."
Indeed
Yess
And this way, science is leading us to refine more and more the knowledge of the world. The orthogenetic model is clearly badly outdated and the signal of what happened is so strong that even with fragments of [once] biological material we manage to accurately predict, correlate and articulate this fascinating story. This video is specially well-crafted and of highly educational value.
I can see knuckle walking coming up in gorillas simply because of their size and weight, as the only solution to both terrestrial and arboreal locomotion. Knuckle walking would be the only way to support and distribute that much mass while still allowing the kind of joint and foot structure that would allow good climbing skills. But if chimps are not much larger or heavier than fractionally bipedal ancestors, that explanation would not hold.
In the case of chimps perhaps modern chimps are much better climbers than our last common ancestor, who might have been a jack of all trades but master of none, so to speak. From that ancestor we decided to double down on walking and became us (eventually) and other populations decided to double down on climbing and became chimps and bonobos.
Interesting question however you slice it.
It’s all about the environment: jungle, mosaic woodland, etc. The structure of the trees our ancestors were in influenced our arboreal locomotion. V different from the trees that other great ape ancestors evolved in.
I owned of that book as a child, and read it constantly.
Super interesting. We had that Time-Life book in the house when I was growing up as well as many others they published on ancient history, natural history, archeology & anthropology (long before wikipedia & the internet we had these things called encycopedias.) It's been fascinating to see how much the natural sciences have grown & changed & advanced technologically. Are these new discoveries adding to the Out Of Africa theory or are they starting to cast doubt on its validity?
Between the Time-Life books, World Book Encyclopedia and Encyclopedia Britannica, I had a great time growing up.
This hypothesis is popular these days, and I see the reasons why. But I'm still skeptical. Knuckle-walking is very unique among primates; you see it in gorillas, chimpanzees and bonobos only. And these happen to be our closest relatives. So parsimony suggests a knuckle-walking common ancestor (if gorillas and chimps were more closely related this would not be the conclusion). Darwin was among the first to point out the anatomical similarities between humans and these specific apes, and thus proposed that our ancestry was in Africa (he's given too little credit for this specific part). That the anatomy of the gorilla is more "columnar" is not surprising; it's heavier than chimps. Given that Ardipithecus was already bipedal I wouldn't expect there to be much evidence in its wrists.
You may well be right, of course we’ll need a lot more fossils to get a better picture.
I think the focus on knuckle walking-as opposed to quadrupedalism in general-is a bit of a diversion: many primates use all four limbs to bear weight, walk and run. So, while knuckle walking is rare (it has been observed in some baboons, as well), quadrupedalism is anything but. To me the question isn't why did chimps/apes evolve to knuckle walk (although they question of whether they did so independently/separately obviously has implications for the human evolution). Rather, the key question for me in this area is why did the ancestors of gorillas and chimps evolve to rely on terrestrial quadrupedalism instead of terrestrial bipedalism.
Interestingly, giant anteaters also knuckle walk. Possibly as an adaptation to their long claws. And pangolins sometimes
@@Grey_Ocean2023knuckle-walking might be caused by specialisation in brachiation in the first place. No other species of extant apes (aside from us) is as terrestrial as gorillas and chimps (and bonobos). But the high level of terrestriality is likely to be secondary to brachiation in the trees. Both, the palms and feet of gorillas and chimps are highly specialised. On the other hand, those of Ardi were quite primitive, in many respects more similar to Proconsul and some other stem apes. If the LCA of hominins and chimps was a specialised brachiator and knuckle-walker this would require evolutionary reversion in Ardi, which is also not very parsimonious. When it comes to your question - why terrestrial quadrupedalism instead of bipedalism in gorillas and chimps? Well, monkeys (sensu simians) are generally quadrupedal, so this seems to be the most obvious posture. What's more the adaptations to brachiation (as well as to vertical climbing), observable in gorillas and chimps would require far more changes to adapt to terrestrial bipedalism than to quadrupedalism. The primitive condition represented for example by Proconsul is a way better starting point. Ardi and presumably the LCA with chimps differed from Proconsul by their broad chest and position of scapulas. Those features are traditionally interpreted as brachiation connected. The original descriptors of Ardi suggest those served a more general increase in arm mobility, being good preadaptation to brachiation, but not being directly related to it. I guess our LCA with chimps never went into brachiation as far as chimps did. But this thesis of course would require a parallel evolution between gorillas and chimpanzees. I only meant to show this hypothesis is plausible. On the other hand, I can buy separate knuckle-walking evolution, but what about brachiation - more or less expressed in all living apes aside from us? Are our 'primitve' features (more Proconsul-like) really primitive, or are those reversals? Those features include manus and foot construction. So this is not like that I have no doubts about the hypothesis.
@@StefanMilo Absolutely, and not just hominin fossils; imagine if we find early chimp-ancestors that were NOT knuckle-walkers for instance, that should add complexity to the overall picture (and make the case for independent evolution of knuckle walking).
That was quality Udo Lindenberg footage you chose there. Thumbs up from Germany!
Philosophically, this inspires me to live and think more like a prehistoric animal. Their deep knowledge is in our cells, we just have to listen
I've got a few skeletons in the closet he might be interested in
The bodies in my fridge prove evolution
@@mez1600bodies in your fridge? What do u mean by that?
That's the difference between science and dogma. Science adapts according to the evidence.
The Stefan Syllogism, as formulated by numerous independent scholars: 1. A characteristic trait of modern humans is storytelling. 2. Stefan is a great storyteller. 3. Therefore, Stefan is a human. This wild hypothesis remains to be tested.
We were also wrong about the 'Big Bang' theory.
“We”?
Are you a cosmologist Chuckles? You just seem really smart,, like scientist level smart.
What about it is wrong?
bazinga
just wanted to come back and watch this amazing video again after reading about Anadoluvius turkae. the level of research and the amount of effort you put into these videos is greatly appreciated
IN THE BEGINING GOD CREATED THE MAN AND THE FISHES
alex murray
@@alexmurray4988 and on the sabbath he rested
@@amogus400 Wabingus
@@mez1600 mez
Funny - a quick review of comments reveals that I'm not the only child that was fascinated by that Time LIfe Evolution book back in the early '60s. For a hoot, check out another book from that era (1959) "All About Prehistoric Cave Men" - another incredibly fascinating book for a child back then. I'm pretty sure all those theories contained within have been de-bunked by now....
😂😂😂😂 I can’t people still believe this bs
It has by far the most evidence supporting it, what would you suppose?
@@alexmurray4561 Really there are just to many problems with it let’s start we came from fish supposedly so there would be an evolution of the fish going through changes all the way to man and there would then be a lot of fossil records it would be impossible for there not to be any showing us the changes correct. The problem is there are none. So just right here we prove man came from man we find a lot of fossil records from man. I can give you a years worth of evidence but if it’s your mind already set your going to continue with this bs evolution myth
Firstly, the lack of a fossil record would not prove that man can from man, that would only prove that there is no fossil record supporting it, there is more than enough evidence from DNA to support evolution. Secondly, ‘the problem is there are none’ this is wrong, the fossil record supports the evolution of Placodermi (jawed fish) into Coelacanth (bony fish) into Panderichthys (fish with the beginnings of 4 limbs, a two lobed brain, and spiracle eyes) into Tikalliik and Acanthostega (more distinct limbs, a rib cage and lungs) into Ichthyostega (no scales, eardrums, stronger bones, the beginnings of fingers, tear glands for wet eyes out of water) into Pederpes (shell-less eggs, an early nose, tongue, salivary glands, thyroid glands, the three-chambered human heart, bladders and most importantly 5-fingered hands) into Hylonomus (first reptile, keratin used for claws (the material in hair and fingernails) sharp teeth, and no gills, adrenal glands, dry scaled skin, more advanced brain system) into Therapsids (no scales, no gastralia, probably warm-blooded, secondary palate (eating and breathing at the same time like we can) and advanced jaws) into cynodonts (advanced lungs, advanced rib cages, lymphatic systems and immune systems, orbital bones and mammalian jaws) into eucynodontia (first mammals, devolved from 4 colour to 2 colour vision, advanced smell system, neocortex In the brain, prostate gland, advanced eardrums, sweat glands and fur, four-chambered hearts (exactly like humans), peni ses, fully separated teeth, SRY gene (differences between sexes)) into Therians (nipples, anal and genitalia, advanced hearing and most importantly live birth (no eggs), Euarchonta (only two nipples (like humans) and opposed fingers) Early primates (expanded brain with 4 pairs of lobes) specialised metabolism lost the ability to produce Vitamin C (like us), claws turned into nails) into Simians (hunted in the day, no claws, sinuses, and a menstrual cycle) into Catarrhini (three colour vision (like us), tooth enamel, shorter arms (like us), no tail, and bigger brain) into Homindae (shorter noses, wide flat ribcage, strong spines, shoulder blades) into Hominini (voice box, larger brain and flexible wrists and elbows) into Australopithecus (walks on two legs, better pregnancy, ate meat as well as plants) and so on to the Homo genus.
@@alexmurray4561 What do you mean by lack there is zero which means evolution is false
@@alexmurray4561 you say all this but we find zero fossils to prove it but we find a lot of man fossils that didn’t evolve it’s a regular fossil it doesn’t take a genius to know if you don’t have physical proof don’t push your narrative on me
The last common ancestors, live in the Democrat cities. I've seen them.
Who are they?
@@elijahfreeman5299 You're one of them.
@Jan PhD You won't answer. Hmm wonder why..you are afraid to.
Please stop just no
Spread of grasslands could have encouraged them to duck down low when moving between trees, to stay safe from predators, leading to knuckle walking.
That’s my professor!! An amazing teacher, he is so passionate about this subject.
Fascinating revelations and implications in this video - bipedalism vs knuckle-walking. Stefan, I must commend you on te overall composition and execution of this episode. It was truly a "professional" product. Camera angles, lighting, audio quality, and especially the balance between interview, discussion, and musical elements. Right on!
*OnLy EviLViLeDeMonics actuaLLy BeLive that MaryAnn Mutated from someChimp!!!*
Love the bipedal gibbon! That makes so much sense. So as the forests were turning into savannas three lineages of apes were experimenting with how to move between the stands of trees most efficiently. One did it on 2 legs and two did it on all fours, and they were all successful because they all still exist today.
That book at the beginning - I had that book as a kid! Still fascinated by this topic.
Aquatic ape hypothesis for the win!
my mom had that book when I was a child, it was instrumental in getting me interested on paleontology
I have a co-worker who looks like the guy from the thumbnail. We are friggin close to apes.
we are apes