Episode 361: The New Hominin

Welcome to 2024! Let’s learn about some exciting new discoveries in our own family tree!

Further reading:

476,000-Year-Old Wooden Structure Unearthed in Zambia

Mysterious 300,000-year-old skull could be new species of human, researchers say

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s time to start the new year off with an episode that has me really excited. I was initially going to include this in the updates episode that usually comes out around summertime, but I just can’t wait. In 2023, scientists discovered what they think might be a new lineage of extinct human ancestors!

We’ll come back to that in a moment, but first I want to highlight another amazing human-relateded discovery from 2023.

And just to let you know, I am going to be using the words “humans” and “people” and “hominins” more or less interchangeably. I try to make it clear when I’m talking about Homo sapiens versus other species of ancient hominin, but these are all our ancestors–in many cases our direct ancestors–so they’re all people as far as I’m concerned.

As you may know, especially if you’ve listened to previous episodes where we’ve discussed ancient human ancestors, the ancestors of all humans evolved in Africa. Specifically, we arose in the southern part of Africa, in areas that had once been dense forest but gradually changed to open woodland and savanna. Because there weren’t very many trees, our far-distant hominin ancestors, the australopiths, no longer needed to be able to climb trees as well as their ape cousins. Instead, they evolved an upright stance and long legs to see over tall grasses, and the stamina to run after the animals they hunted until the animal was exhausted and couldn’t run anymore. Once our ancestors were walking on two legs all the time, their hands were free to carry babies and food and anything else they wanted.

Being fully bipedal meant that women had a harder time giving birth, since the pelvis had to change position to allow them to walk and run, so babies started being born when they were smaller. This meant the babies needed a whole lot more care for a lot longer, which meant that family groups became even more important and complicated. One thing we’ve learned about sociability in animals is that it leads to increased intelligence, and that’s definitely what happened with our long-distant ancestors. As their brains got bigger, they became more creative. They made lots of different types of tools, especially weapons and items that helped them process food, but eventually they also made artwork, baskets, clothing, jewelry, and everything else they needed.

All this took a long time, naturally. We know Australopithecus used stone tools over three million years ago, but we don’t have evidence of human ancestors using fire until a little over 1.5 million years ago. Homo sapiens was once thought to have only evolved around 100,000 years ago, maybe less, but as scientists find more remains and are able to use more sophisticated techniques to study those remains, the date keeps getting pushed back. Currently we’re pretty certain that actual humans, if not the fully modern humans alive today, arose about 300,000 years ago and maybe even earlier. Homo sapiens evolved from Homo erectus, which arose about two million years ago and went extinct about 100,000 years ago. They were probably the first hominin to use fire, which allowed humans to start migrating longer distances into colder climates. They might also have communicated with language. Basically, Homo erectus was a lot like us but not quite us yet.

The modern-day country of Zambia is in the middle of south-central Africa, and naturally it’s been home to humans and our ancestors for as long as humans have existed. One especially important part of Zambia is also one of its most beautiful places, Kalambo Falls, which is really close to the equally important and beautiful country of Tanzania. Scientists have known that humans of one kind or another have lived around Kalambo Falls for at least 447,000 years, long before Homo sapiens actually evolved.

When a team of archaeologists excavated a sandbar near the falls in 2019, they were surprised to find wooden artifacts. Wood doesn’t usually preserve for very long and the site they were excavating was quite old. In addition to wooden tools, they found two logs that had been shaped and notched to allow them to fit together securely. The researchers thought the logs had once been part of a structure like a walkway that would keep people’s feet out of the mud and water, or possibly the floor of a wooden structure used to store food. It might even have been the floor of a little house.

Wood can be dated with simple tests to find out its age, but the test is only useful for trees that died within the last 50,000 years. Anything older than that is just, you know, older than 50,000 years. The tools and logs tested as older, which the scientists expected. Fortunately there are other ways to date older wood, but the results of those tests were surprising even to the scientists. The tools were at least 324,000 years old, possibly as much as 390,000 years old, but the logs were even older, about 476,000 years old.

Remember, Homo sapiens didn’t even evolve until about 300,000 years ago. That means humans didn’t make those tools or build anything with those shaped logs. Some other hominin did, although we’re not sure who. Even more exciting, close examination of the logs suggests that they may have been subjected to fire at some point. That might mean a natural fire or it might mean that the people who were building with the logs were also using fire as much as two million years before we thought people were using fire.

Obviously scientists are going to look carefully for more clues about who might have shaped these logs and when. Hopefully we’ll learn more soon.

Around the same time that scientists uncovered the wooden items in southern Africa, another discovery was made in 2019, this one in East China. A team found a jaw, skull, and leg bones of a hominin that didn’t match up to any known human ancestor. The bones were dated to 300,000 years ago, at the dawn of Homo sapiens. Other hominins had migrated to eastern Asia long before this, however, including populations of Homo erectus.

The newly discovered bones don’t belong to Homo erectus, though. They don’t belong to Homo sapiens either, or any other known hominin. They represent a completely new hominin, and at the moment scientists don’t know where exactly they fit in our own family tree.

The bones show traits found in modern humans, like a flat face, but lack other uniquely human traits, most notably a chin. Homo sapiens have chins, unlike every other hominin, and no one’s sure why. It might have something to do with speech or maybe early humans with chins were just considered more attractive, and now everyone has a chin.

The mystery hominin is still being studied, but preliminary findings indicate that we might have discovered the ancestor of a very close relation. The bones show some traits also found in Neandertals, our very closest evolutionary cousins, even though they’re extinct. There’s a possibility that this new hominin gave rise to another line of very close human relations, one we don’t have any fossils of yet.

I know there are a lot of excited scientists wanting to learn more about the hominin bones. Hopefully more bones will turn up soon so we can get a better idea of who this distant relative is. It’s a little too early to throw them a welcome home party, but maybe we can start planning it now.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 026: Humans Part Two

Part two of our humans episode is about a couple of our more distant cousins, the Flores little people (Homo floresiensis) and Homo naledi, with side trips to think about Rumpelstiltskin, trolls, and the Ebu gogo.

Homo floresiensis skull compared to a human skull. We are bigheaded monsters in comparison. Also, we got chins.

Homo naledi’s skull. I stole that picture from Wits University homepage because I really liked the quote and it turns out it’s too small really to read. Oh well.

Some of our cousins. Homo erectus in the middle is our direct ancestor. So is Lucy, an Australopithecus, although she lived much longer ago.

Show transcript

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week is part two of our humans episode. Last week we learned how modern humans evolved and about two of our close cousins, Neandertals and Denisovans. This week, we’re going to walk on the weirder side of the hominin world.

Before we get started, this episode should go live on July 31, 2017, one week before I fly to Helsinki, Finland for WorldCon 75! Don’t worry, I’ve got episodes scheduled to run normally until I get home. If you’re going to be in Finland between August 8 and August 17, let me know so we can meet up. On Thursday, August 10 and 4pm I’ll be on a panel in room 207 about how to start a podcast, so check it out if you’re attending the convention. I’ll also be in Oslo during the day on August 7 and have two birding trips planned with lunch in between, and I’d love you to join me if you’re in Oslo that day too. Then, two weeks after I return from Finland, I’ll be attending DragonCon over Labor Day weekend. blah blah blah this is old news

Now, let’s learn about some of our stranger distant cousins!

In 2003, a team of archaeologists, some from Australia and some from Indonesia, were in Indonesia to look for evidence of prehistoric human settlement. They were hoping to learn more about when humans first migrated from Asia to Australia. One of the places they searched was Liang Bua cave on the island of Flores. They found hominin remains all right, but they were odd.

The first skeleton they discovered was remarkably small, only a bit more than three and a half feet tall [106 cm] although it wasn’t a child’s skeleton. That skeleton was mostly complete, including the skull, and appears to be that of a woman around 30 years old. She’s been nicknamed the Little Lady of Flores, or just Flo to her friends. Officially, she’s LB1, the type specimen for a new species of hominin, Homo floresiensis.

But until very recently, that statement was super controversial. In fact, there’s hardly anything about the Flores remains that aren’t controversial.

At first researchers thought the remains were not very old, maybe only twelve or thirteen thousand years old, or 18,000 at the most. Stone tools were found in the same sediment layer where Flo was discovered, as were animal bones. The tools were small, clearly intended for hands about the size of Flo’s, which argued right off the bat that she was part of a small-statured species and wasn’t an aberrant individual.

The following year, 2004, the team returned to the cave and found more skeletal remains, none very complete, but they were all about Flo’s size. Researchers theorized that the people had evolved from a population of Homo erectus that had arrived on the island more than three quarters of a million years before, and that they had become smaller as a type of island dwarfism. A volcanic eruption 12,000 before had likely killed them all off, along with the pygmy elephants they hunted.

But as more research was conducted, the date of the skeletons kept getting pushed back: from 18,000 years old to 95,000 years old to 150,000 years old to 190,000 years old. Dating remains in the cave is difficult, because it’s been subject to flooding and partial flooding over the centuries. Currently, the skeletal remains are thought to date to 60,000 years ago and the stone tools to around 50,000 years ago.

When news of the finds was released, the press response was enthusiastic, to say the least. The skeletons were dubbed Hobbits for their small size, which made the Tolkien estate’s head explode, and practically every few weeks it seems there was another article about whether there were small people still living quietly on the island of Flores, yet to be discovered.

And, of course, there were lots of indignant scientists who were apparently personally angry that the skeletons were considered a new species of hominin instead of regular old Homo sapiens. Part of the issue was that only one skull has ever been found. It’s definitely small, and the other skeletal remains are all correspondingly small, and the stone tools are all correspondingly small, and the skull shows a number of important differences from that of a normal human. But that doesn’t necessarily mean it’s not a subspecies of Homo sapiens, and of course that needs to be investigated. But some of the arguments got surprisingly ugly. There were even accusations that the entire find was faked. One person even suggested that the skull’s teeth showed evidence of modern dental work.

Amid all this, two unfortunate things happened. First, in December 2004 an Indonesian paleoanthropologist named Teuku Jacob removed almost all the bones from Jakarta’s National Research Centre of Archaeology for his own personal study for three months. When he returned them, two leg bones were missing, two jaw bones were badly damaged, and a pelvis was smashed. Then, not long after, Indonesia closed access to Liang Bua cave without explanation, although the archeological community suspected it was due to Jacob’s influence, and didn’t reopen it until 2007 after Jacob died.

It’s important to note that Jacob was a proponent of the theory that the remains found in Liang Bua cave were microcephalic individuals of the prehistoric local population, not a new hominin species at all. He also had a history of keeping Indonesian fossils from being studied unless he specifically approved of the research.

At any rate, since then, repeated studies of the LB1 skull have suggested that Homo floresiensis is a separate species of hominin and not a Homo sapiens with evidence of pathology, whether microcephaly or another disease, or a population with a genetic abnormality. There’s still plenty of research needed, of course, and hopefully some more skulls will be found. But it seems clear that Homo floresiensis isn’t just a weird subspecies of Homo sapiens.

One of the more common theories in the last few years was that Homo floresiensis was descended from Homo erectus, although Homo erectus was a lot bigger and more human-like than the Flores little people. But results of a study released just a few months ago show that Homo floresiensis shared a common ancestor with Homo habilis around 1.75 million years ago. Homo floresiensis may have evolved before migrating out of Africa, or their ancestor migrated and evolved into Homo floresiensis. Either way, they spread as far as Indonesia before dying out around 50,000 years ago.

Other hominin remains have since been found on the island. Part of a jaw and teeth were found at Mata Menge on the island of Flores, some 50 miles away from the cave. It’s around 700,000 years old and is a bit smaller than the same bones in the later skeletons. Researchers think it’s an older form of Homo floresiensis.

Possibly not coincidentally, modern humans arrived on the island about 50,000 years ago, maybe earlier, bringing with them the arts of fire, painting, making jewelry from animal bones, and killing all of our genetic cousins.

We don’t know if humans deliberately killed the Homo floresiensis people or if they just outcompeted them. It does seem pretty certain that the two hominin species coexisted on the island for at least a while. It’s even possible that knowledge of the strange small people of the island has persisted in folk tales told by the Nage people of Flores. Stories about the ebu gogo have been documented for centuries. They were supposed to be little hairy people around three feet tall [one meter], with broad faces and big mouths. They were fast runners with their own language and would eat anything, frequently swallowing it whole. In some stories they sometimes kidnapped human children to make the children teach them how to cook, although the children always outwitted the ebu gogo.

Supposedly, at some point, tired of their children being kidnapped and their food being stolen, villagers gave the ebu gogo palm fibers so they could make clothes. The ebu gogo took the fibers to their cave, and the villagers threw a torch in after them. The fiber went up in flames and killed all of the ebu gogo.

Until the discovery of Homo floresiensis, anthropologists assumed the stories were about macaque monkeys. But there’s a genuine possibility that the ebu gogo tales are memories of Homo floresiensis. It’s not just cryptozoologists and bigfoot enthusiasts making the connection between the ebu gogo and Homo floresiensis. Articles and editorials have appeared in journals such as Nature, Scientific American, and Anthropology Today. At least, they did back when archeologists thought Flo was only about 12,000 years old.

But we still don’t know for certain when Homo floresiensis went extinct. There may be remains that are much more recent than 50,000 years ago. Locals mostly say there are no ebu gogo left but that they were still around about a century ago. I don’t know how long historical elements can persist in an oral tradition without becoming distorted. As we discussed in episode 17, about Thunderbird, oral history is easily lost if the culture is disrupted by invasion, disease, war, or other major episodes. But some stories are tougher than others, and those that are less history and more entertainment—although they may contain warnings too—can be very, very old.

Researchers have traced some traditional folktales, like Rumpelstiltskin, back some 4,000 or even 6,000 years, although not without controversy. But while Rumpelstiltskin is usually described as a small person, no one’s suggesting that story is about real events. It’s the juxtaposition of the Flores discoveries of small skeletons and the oral tradition or small people living on the island that got researchers excited. And as it happens, there is an oral tradition many miles and many cultures away from Flores that might be something similar.

Old Norse stories about trolls date back thousands of years. The trolls vary in appearance and sometimes have a lot of overlap with other monsters, but generally are described as big and strong, not very smart, often placid unless provoked, and usually evil, or at least godless. Sometimes they capture humans who outwit them to escape. In one story, a man named Esbern Snare wanted to marry a woman, but her father would only agree to the marriage if Esbern would build a church. Esbern struck a deal with a troll, who said he would build the church—on one condition. If Esbern couldn’t guess the troll’s name by the time the church was built, the troll would demand as his payment Esbern’s heart and eyes.

Esbern agreed, but he failed to trick the troll into telling him his name. On the final day, in despair Esbern threw himself down on the bank of a river, where he overheard the troll’s wife singing to her baby:

“Hush, hush, baby mine,

Tomorrow comes Finn, father thine,

To bring you Esbern’s heart and eyes

To play with, so now hush your cries.”

Esbern rushed back to the church and greeted Finn the troll by name. In some version of the story, Finn is so furious that he leaves the church incomplete in some way, usually a missing pillar. For those of you who aren’t familiar with the Rumpelstiltskin story, that’s a variant. Oh, and Esbern Snare was a real person who lived in the twelfth century, although I’m pretty sure he didn’t actually strike any deals with trolls.

But I do wonder if some elements of troll folklore might be derived from memories of Neandertal people. I’m not the first to suggest this, although it is a pretty fringey theory. And in the end, we just don’t have any way to know. But it is interesting to think about.

As you may remember from part one of the humans episode, Homo sapiens evolved roughly 200,000 years ago. But around the same time, or a little earlier, another cousin in our family tree was living in southern Africa. Remains of Homo naledi were only discovered in 2013 by some cavers. Partial skeletons from at least 15 individuals were recovered in one field season, but due to narrow cave passages, the field work had to be done by people of small stature who weren’t claustrophobic, mostly women.

Homo naledi is a mixture of primitive and advanced features. Primitive in this case means more like our ape ancestors, and advanced means more like modern humans. Homo naledi had long legs and feet that looked just like ours, but also had a small brain and fingers that are much more curved than ours—not characteristics that would look out of place a few million years ago, but surprising to discover in our family tree at about the same time that modern humans were evolving.

On the other hand (with curved fingers), evolution doesn’t have an end goal. Homo sapiens is not the pinnacle of creation to which all other living beings aspire. We’re just another animal, just another great ape. If Homo naledi was successful in their environment with a small brain, that’s all that matters from an evolutionary standpoint.

There are lots of remains left in the cave, so many in fact that some researchers are convinced they didn’t get there by accident. It’s possible that the cave was used as a burial pit, maybe even over the course of centuries. Bodies may have been dropped in a deep shaft and were then moved by periodic flooding to the remote chamber where they were found, or they may have been carried to the cave depths and left there.

Homo naledi wasn’t a direct ancestor of Homo sapiens, but they were definitely a kind of human—no matter how small their brains may have been.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes for as little as one dollar a month.

Thanks for listening!