The Missing Link That Wasn’t


It’s 1912, and an amateur archaeologist
named Charles Dawson came forward with a discovery that almost changed our understanding of human
evolution. Almost. Dawson’s find was some unusual human-like
skull fragments, and he showed them to the Keeper of Geology at the British Museum, Sir
Arthur Smith Woodward. He explained that the fragments were given
to him by some gravel quarry workers near the town of Piltdown in England a few years
earlier. So the two men returned to the site and find
some additional animal fossils that provided an estimated age for the skull bones: Early
Pleistocene, making it the oldest evidence of a human ancestor ever found. The excitement then continued with the discovery
of a lower jaw that seemed to match the skull. But it’s teeth were odd; the molars showed
patterns of wear that were similar to those found in humans. And a canine discovered later at the same
site was intermediate in size between ape and human canines. With its large cranial capacity — close to
that of modern humans’ — Dawson’s fossil closely matched what experts thought a human
ancestor was supposed to look like at the time. It was named Eoanthropus dawsoni and was hailed
as a “missing link” in our family tree. And this fossil was also … fake. Totally made up. What’s known today as the Piltdown Man hoax
is probably the most famous evidence you’ll ever find that, even in science, bad ideas
take a long time to die. In this case, the idea was that of the Missing
Link — the idea that somewhere out there, there had to be some hypothetical specimen
that would partly resemble an ape but also partly resemble a modern human. But, there is no missing link in our lineage,
because that’s not how evolution works. And the fact is, the search for the Missing
Link was just one phase in the evolution of our thinking about … human evolution. The idea of a “Missing Link” has fascinated
people for as long as we’ve been studying our origins. But most scientists today don’t use that
term to talk about the fossil record, because evolution is a lot more complicated — and
way weirder — than just a series of species lined up single-file. So, the changing ideas about the existence
of a “Missing Link” are closely tied to how the prevailing thinking about evolutionary
theory in general has changed. The oldest model for thinking about change
over time was known as orthogenesis, which presents a linear model of evolution, with
species progressing from one form into the next toward some kind of goal or ideal. And in the early 19th century, evolution was
thought to be linear, based on the premise that species evolve from other species, and
that forms between the two should have physical traits that resemble both the older and the
younger forms. Linear evolution is usually depicted as the
so-called March of Progress, an image that’s still very popular today. And the idea of linear evolution made it easy
to accept the Piltdown Man as a ‘Missing Link,’ because it reflected that logic:
It was a creature that was halfway between a human and other great apes. But the PiltdownMan hoax overshadowed the real, legitimate
fossil discoveries that were being made around the same time, all over the world. For instance, there was Java Man found in
Indonesia in 1891, and Peking Man discovered in the 1920s in China, both specimens
of Homo erectus. These finds were largely overlooked, because
they didn’t fit another bad idea of the time — namely, that the first modern human
feature to evolve was our large brain. Compared to the so-called Piltdown Man, Java
Man and Peking Man had small brains and smaller, human-like canines. And not only were these Asian discoveries
dismissed, but Africa was also left unexplored in the search for human origins. The reasons for this had more to do with social
politics than science, including the widespread bias against the notion that the first humans
were Africans. But in 1924, while Piltdown Man was still
enjoying considerable fame, limestone workers in the town of Taung, South Africa discovered
a fossil that they presented to anatomist Raymond Dart. It was the tiny partial skull and endocast
of a juvenile primate, which Dart called the Taung Child. He eventually gave it the scientific name
Australopithecus africanus, the southern ape from Africa. And for a while, Dart himself wondered whether
this child represented a missing link. But the evidence he found flew in the face
of conventional wisdom. It was clear from the fossil that the Taung
Child had a small brain, and human-like teeth — the exact opposite of Piltdown Man. The discovery was widely criticized among
European researchers — including, unsurprisingly, the supporters of the Piltdown Man hoax. But the Taung Child’s strange combination
of features, along with those other finds from Asia, convinced some prominent anthropologists
that maybe our evolution wasn’t as linear as they’d thought. Adding to the debate, major doubt was cast
on Piltdown Man in the 1930s when a geologist mapped the gravel around the site and closely
correlated it to the River Thames deposits. So how could an ancient hominin be buried
in modern sediment? Finally, in the 1950s, Piltdown Man was, at
long last, debunked as a fraud. Fluorine tests, and later, carbon dating revealed
that the fossils weren’t from the Early Pleistocene — they were more like 600 years
old. And the jaw probably came from an orangutan
whose teeth had been filed to look like it was part-way between an ape and a human. Using microscopes, researchers revealed miniscule
scratches left behind by the file on the unnaturally flattened molars. The Missing Link was never missing; it turns
out, it had never existed at all. As more fossil discoveries were made throughout
Africa in the mid 20th century, the linear model of evolution was abandoned. Instead, these finds gave rise to a new way
of thinking: phylogeny, which depicts evolutionary relationships as branching trees. This Branching Tree model took a slightly
more complicated approach to human evolution, acknowledging that not every fossil discovered
was directly ancestral to us. Also that ancestor and descendent species
could overlap in time. Additionally, this model demonstrated that
there were many branches off the main trunk, resulting in ‘evolutionary dead ends’
— species that went extinct without leaving any modern descendants. These side branches included sister taxa like
the Paranthropines from East and South Africa. Who were robust hominins with large teeth
and wide faces that did not fit the criteria to be our ancestors. So the Branching Tree model was an improvement
over the old March of Progress. And for a while, we thought it was what human
evolution looked like. But then at the turn of the 21st century,
new technology for sequencing ancient DNA – like from Neanderthals and Denisovans – came
along. And new fossil species were discovered that
lived at the same time, like Australopithecus sediba, which overlapped in time with Homo
habilis. These developments revealed that our family
tree was a lot more complicated than just a branching tree or bush…and that it was
time to update our model. It’s now called the “Braided Stream”,
a new way of thinking about human evolution that takes into account our interbreeding
with other hominin species. The Braided Stream is something that biologists
and geneticists have seen in animals for years, but it has only recently been applied to humans. It depicts evolution as a series of channels
that sometimes branch off each other, but also sometimes reunite at various points. And as different lineages shared genes, it
resulted in hybridization. This model captures crucial information that
was missing from the Branching Tree model: It shows how species can reconnect after their
initial split from a common ancestor. And it highlights the importance of gene flow
in our evolution as a species. So instead of searching for missing links
in the fossil record, the search has begun instead for fossils that show evidence of
gene flow, physical proof of what we know from our DNA, that all of us are a product
of interbreeding. And even before DNA sequencing, some researchers
used experimental studies to figure out what hominin hybrids might have looked like, and
to determine if we may have already found some in the fossil record. Experimental models on baboons, for example,
have shown that hybrids tend to be larger than either of their parents, and they tend
to have large teeth and extra bone-joints, called sutures, in their skulls. So based on studies like these, researchers
think we have already found fossil human hybrids! A jawbone found in Romania dating back some
40,000 years, for example, has been found to have had both Human and Neanderthal ancestry. Experts could tell this not only because of
variations in its teeth and jaw, but it was later confirmed with its DNA, which showed
that the hominin had a recent Neanderthal ancestor four to six generations back. So, the Braided Stream model accounts for
the fact that some hominins didn’t view other types of hominins as that different. And because of our close evolutionary relationships,
we were able to reproduce with them and carry our combined genes into the next generation. The evolution of evolutionary thinking has
gone from a simple linear model to an increasingly complex branching tree and now a braided stream. And the more complex we realize that our evolution
has been, the more remarkable it seems! It’s the product of multiple populations,
over millions of years, existing together, and exchanging genetic material. It aided our process of adaptation that allowed
us to thrive in a range of environments all over the world. Through the combination of DNA studies, fossil
discoveries, and experimental data on hybridization, we’re still trying to create the most complete
depiction possible of our human family. And now we can all stop looking for — or
inventing fake versions of — a ‘Missing Link,’ because we know that a fossil that
is ‘half human and half ape’ simply does not exist. It’s taken a hundred years and many changes
in our thinking, but we’ve come a long way from Piltdown, the greatest hoax ever to rock the
world of human origins – the missing link that wasn’t. Thanks to this month’s Eontologists: Patrick
Seifert, Jake Hart, Jon Davison Ng, and Steve. If you’d like to join them and our other
patrons in supporting what we do here, then go to patreon.com/eons and make your pledge! And also thank YOU for joining me today, in
the Konstantin Haase Studio. If you want more adventures in deep time,
just go to youtube.com/eons and subscribe.

Comments 100

  • The definition of the term "Species" I learnt said that, if two specimen could generate fertile offspring, they belonged to the same species. As we find Neandertal genes in modern humans, there cannot be a species barrier seperating us from Neandertalians.

  • The title sounds like something that you would find on YGS

  • I do think it is even more complex then the braided stream for there is no reason to assume the interbreeding genes will spread through the complete population. Groups will always be isolated from other groups.

  • 💞💞💞💞

  • The fundamental problem with using small changes in bones over time as aproxy for small changes in genes over time is that these are not the same thing. As soon as genetic materials enters the discussion, thoughtful advances in theory occurs. Here is to more such more such genetic based evaluations, revaluations, improvements and general use of data to advance scientific conjectures.

  • The biological definition of a species is that individuals of different species are reproductively isolated(ie cannot produce fertile offspring) whether it be mechanically, behaviourally or geographically based. So I guess my question is, how does this definition change now that we have evidence of distinct hybridization events that produce fertile offspring?

  • Aboriginal Australians are a missing link. 40000 years of isolation.

  • Cali is the best !!!

  • They do anything for clout smh

  • Evolution due cosmic rays penetrating earth.

  • Certainly this is fuller depiction of evolution, but you can not have branches floating in the air without MISSING LINKS connecting them to the trunk. You have left unswered the absence of missing links.

  • s m a l l b r a i n

  • The missing Link is sleeping in the Temple of Time

  • I find reconstructions of Neanderthals sexy…

  • Speaking of how long it takes to kill a bad idea, how long until postmodernism is killed off in the human sciences?

  • Still might be a missing link if I'm judging the last image correctly. Are there really no more traces of Homo Erectus in living people anymore?

  • The “braided stream” thing has always confused me. This is the first time I’ve heard that term, but the idea of interbreeding species is what’s confuses me.

    From my knowledge species are defined by their inability to mate with close relatives. Perhaps my definition is wrong, but under that definition of species: how are different species interbreeding?

  • The issue isn’t that there is “a” missing link, but that there is no evidence of ANY transitional forms where there should be millions!

  • I had a biology professor once who was adamant about the species definition as "individuals who can produce viable offspring". Is this also an outdated idea? As the braided stream idea looks at interbreeding between humanoid species?

  • Do a video about haast's eagle!!

  • And who was that missing link? You guessed it……. Frank Stallone.

  • Im sleepy as f.

  • I used to work with the missing link.

  • What up fellow INTERBREDS 🤣 Btw this video like all others of Eons was amazing but pretty important too (We have to stop being dogmatic & be more accepting of new thinking plus it also points out how we have to thoroughly test something before accepting it). Love the channel 😘🤗

  • Modern humans is a results of hybridization? Not sure if "some folks" are going to agree with this

  • You “forgot” to mention the Annunaki inter-species breeding.

    Genesis 6

  • The school still can't teach how evolution works properly. Tsk tsk

  • I still don't understand how different species can interbreed with eachother. Isn't the definition of a species a population which can breed to produce fertile offspring?

    So if two individuals from different species interbreed to produce fertile offspring then shouldn't they actually be from the same species?

  • 6:30 deserves to be a meme

  • The key word is millions of years Now it becomes believable.

  • Very interesting episode as usual! I might have missed it, but when did the braided stream evolutionary model emerge? I only studied phylogeny at school, and if not bleeding edge it already felt much more modern than the linear model at the time? It might just have been my perception though. 🙂

  • Just play ancestors

  • It's 1912 and I am viewing this with astonishment on some sort of portable motion picture playing device that projects light and is impossibly thin.

  • Can someone explain to me why if close related species interbreed all the time, then there's the definition that for two species to be different they should not be able to produce fertile offspring? I've always had this doubt.

  • I wrote an assignment on the Piltdown Man in my first year at uni! It was part of a "Theories and thinkers in Biological Anthropology" module. Man, the early anthropologists were really, really unscientific.

  • Simbots are mentally dysfunctional because they don't actually mentally function. Simbots can only "mentally function" within a very short list of programmed presets. Which immediately identifies them as simbots with 100% accuracy.

  • Thank you Steve

  • Bigfoot is the missing link

  • Imagine explaining this to my parents

  • The "Missing Link" is real!

    You can find him at 1600 Pennsylvania Avenue.

  • Still passing off the newest theories as fact. Take a cue from Carl Sagan, occasionally throw in the word “maybe”.

  • "PDS"

  • Why did all those other hominids go extinct, and so quickly too? I would expect some to be around today. After all, they must have been selected for survival to have evolved in the first place.

  • Thought it was found on Pennsylvania Avenue.

  • Why is it if you go to the Smithsonian Institute you will see seven skulls on a Cara fault the two on the left are real the two on the right or real every single one in the center is a guess that someone had. None of the skulls in the center of the table are real, because they have never found any from that era ever that look like what they think it's supposed to look like. And yes I believe silly ideas in science are hard to kill like the fact that there's more than two sexes.

  • Another superb video. It is always a pleasure.

  • Hominids and their trademark rampant scoodly-poopin

  • Check out beothuks in newfoundland that were hunted for sport when when the British came a calling

  • This theory actually makes sense on so many levels. Why would the various iterations of man not interact on a social level, including sexual interactions. Travel and trade would provide many opportunities for such interactions. This theory gives a whole new meaning to the directive: "Be fruitful and multiply, and replenish the Earth." It seems our ancient ancestors may have done just that.

  • Please make a video of how heavy weight creatures made of tons of kgs.. roamed earth without getting crushed.. Even hollow bones helps to explain about getting huge.. still it's not the full answer with gravity in place. Is something missing? . Tons of meat roaming active just with help of hollow bones.. How's it possible? Please explain about it.. Thanks for all your uploads..

  • Believe me, I absolutely love these videos and appreciate all the work put into them, and I know we know close to nothing about the Denisovans, but I feel that we've got to have a better representation than the vaguely humanoid sketch at 9:04. What DO we know or what are we actually able to surmise about their physiology?

  • Check out the YouTube video from: it's okay to be smart.
    Titled: there was no first human.
    imho a better way to describe evolution, especially for a layman like me.

  • So if your hypothesis is correct then how did evolution actually happened then where is the evidence, For instance if there is no missing links and nothing happens linearly in A-line something's may some things may not, Also the 8 family of our tree this not have the DNA that we have a few percent that we do have is totally missing, So although we may be related There's no missing link does not explain where the link is. Are dinosaurs totally different and the whole half a planet got destroyed on this side of the planet killing all the dinosaurs and mammals over here in all the America's everything came from the other part of the world that's not hard to figure out, so what parts of the planet did repopulate life over here, also way way way back the earth tilted

  • Do a Flores man episode! From what I've learned, scientists are split but many don't believe they were genetic abnormal homo sapiens. They anatomically should be in 1-2 million year point in our evolution but went extinct 14-20k years ago, in Indonesia. Not Africa. Appeared to have made tools. Fun topic!

  • Java man had been verified as a baboon
    A 2 inch square of skull bone from above the ear was transferred into a whole skull. These are just a few of incorrect analysis of bone fragments that have been projected to be human. It seems that science is doing everything to promote evolution. With incorrect made up facts. The would make excellent politicians.

  • The theory of evolution is barely a hypothesis. Think the Cambrian Explosion. The world did not get as complex as it is through luck of the draw. Or put more scientifically, "natural selection".

  • Can't find missing link, so make excuses?

  • It is 2019 and people STILL bring up the missing link. This video needs to be spread around lol.

  • When we find Bigfoot/Yeti officially that is the "missing link"

  • There was NEVER a Missing Link because their was Missing Link to be had , and NO , Man did NOT evolve from the ADAPA or PLANET of the APES or Monkeys , Now very early in man's evolution or forward progression he may had a more Primitive appearance , but he was NEVER and Ape or Monkey …………… Smile

  • How about the half man, half bear and half pig? We know the manbearpig exists but it's ancestors?

  • Lets face it with humans. If it walks on two legs they will try and hump it at least once, twice if they come back.

  • c darwin

  • Bad ideas take a long time to Die.
    very true

  • now thats the real interracial progeny

  • Neandertal

  • Sooo you dont know.

  • beautifully simple and clearly reasonable thinking, excelent job!

  • This interspecies breeding should have been very common to leave trails in our genes and the fossil record. I can only guess that the coexistence between different species was not more peaceful nor more violent than between members of the same species

  • IF YOU ENDED THIS VIDEO AT 1:50 I'D LIKE IT MORE, JUST DRAGGING IT ON FOR DEM AD REVENUES

  • Let me get this straight; back in prehistoric time, we actually coëxisted with different human species, not just races, species, and we thought of them as exactly as human as we were… I guess the takeaway here is that racism is a product of modern times…

    Must be those darn video games…

  • Religious fundamentalists are freaking out now…again.

  • Gotcha. This is where Tom Green got his schtick. There were some legendary practical jokers back in the day. They would go all out

  • Hybrids are usually sterile and lack the natural skills imprinted or their DNA needed for adaption in a changing environment. Which means they just die off.

  • But if this early different human species, were capable of mating and generating fecund offspring, were they really different species after all?

  • If homins didn't view other types of hominins as that different, then I assume that racism has 'evolved' much, much later.
    Thank you for this video. I always love it how clearly you PBS people are explaining these subjects.

  • This IS a very touchy subject and I'm glad this information has come to light.

  • So you're telling me I'm not the first to clap ape cheeks

  • Braided stream doesn't remove missing link concept.

  • Am I the only one hearing "missing leenk"??

  • Stupid question: I always thought that hybrids were necessarily sterile. How is it that Homo Sapiens have Neanderthal or Austrolapithicus DNA?

  • Where's my copy of Zelda gone?

  • I'm unsure why the braided stream model doesn't allow for something like a missing link. Are there not still intermediary steps between our current anatomy and earlier species from which we descended? How are those different from a missing link?

  • It was a walking stick

  • It'sss ssso hard to lisssten to thisss lady ssspeak.

  • Wait…. knowing that a fossil that is half human & half ape don't exist? Or is the host trying to say we only find fossils that are half Ape/ half human? I'm a bit confused 🤷‍♂️

  • Remember you are what you eat🍔🍟🍻…Our diet and mental knowledge caused by struggles or curiosity is the drive behind Human Evolution.

  • Do a video on ruminant evolution please!

  • Will scientists ever be able to project where the human evolution might be heading ?

  • Beautifully put together show

  • Where do Denisovans fit in all of this? Particularly in the diagram at 9:18

  • Missing linkn't

  • One way or the other "we" have to be right about evolution. Trust us, we haven't been wrong in nearly a full week.

  • Please cover up those disgusting tats. A PBS youtub channel should be child-appropriate.

  • Perhaps if our ancestors hadn't interbred with Neanderthals and Denisovans, we wouldn't have made it as far as we have.

  • I don't understand the "Braided Stream" model, isn't "capable of interbreeding and creating fertile offspring" the definition of a species? If Humo sapians can do that with Neanderthals, doesn't that mean we are all the same species?

  • Or evolution is a load of crap.

  • This is nice.

  • If we came from monkeys then why are there still monkeys?

  • Infinite diversity in infinite combinations 🙂 Beautiful. It is very cool to know that we all carry the legacy of all those ancestors who came before us. I am thinking of doing of one those DNA heritage tests to see where my patchwork of genes came from 🙂

Leave a Reply

Your email address will not be published. Required fields are marked *