Not the Tolkien ones. You've definitely heard of those.

I'm talking about Homo floresiensis, the famously tiny hominin species from Indonesia.

Our short-statured cousins lived on the island of Flores and only went extinct around 50,000 years ago, which is not that long.

But even though we've been talking about Homo floresiensis for more than a decade here at SciShow, there are still a lot of unknowns about these guys.

And probably the biggest is also the littlest.

Why were they so small?

Well, here's the long and short of it.

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The first Homo floresiensis specimen was found in September 2003 in the Liangboa cave on Flores.

And I was very excited.

I was 23 and I read a lot of science news.

It was a mostly complete skeleton from a roughly 30-year-old female dubbed LB1.

And even though she was an adult, she was just a little over a meter tall, or about the size of a modern four-year-old.

Hence the hobbit nickname.

She was originally estimated to be about 18,000 years old, but newer evidence has pushed that back to around 60,000 years.

And her skull was proportional to the rest of her body, which meant her body and brain volume were basically the size of a chimp.

This was surprising for a number of reasons.

For one thing, her size and brain volume were also similar to australopiths, who lived more than 3 million years ago.

But australopiths went extinct more than a million years ago, and as far as we knew, they never left Africa.

For another thing, the remains were associated with stone tools and evidence of fire and cooking big game.

Someone with such a small brain doing such technologically advanced things didn't really jive with the way we thought about intelligence.

Which is part of why there was a ton of drama surrounding these hobbits pretty much from the second their discovery was announced.

And boy, was it spicy!

With only one skull, some anthropologists didn't believe that this was a valid species, and said that LB1 was probably just a member of another homospecies with some sort of pathology.

Something wrong with her.

So rather than the species being chimpsized with chimpsized brains, we just happened to find one individual who was that small.

Microencephaly, dwarfism, Down syndrome, Lerone syndrome, and different combinations of these have all been proposed for why LB1 was as small as she appeared to be.

Meanwhile, the researchers who found it were adamant that this individual wasn't pathological at all and represented a brand new species.

Papers were flying back and forth, and they did not hold back on the academic shade.

One group went as far as calling another group's work research.

Like, in quotation marks.

This is like the academic equivalent of slapping someone in the face with your glove.

Like, it was going down.

The specimens were then sent to a university in Indonesia for further study under a different researcher, not by the team that made the original discovery.

And this new researcher happened to be firmly on the side of everyone saying that LB1 was pathological.

This researcher would only let other researchers who were also on team pathology examine the fossils, essentially limiting research to just the stuff that would confirm what he already believed.

Even worse, when the bones were eventually returned, they were damaged.

Some people think the damage happened during transit between locations, but others accused the researcher who had them of causing the damage directly due to poor research practices.

The tea was piping hot, and I, for one, demand a Netflix documentary about this immediately.

But as these things tend to go, time marched forward, and more evidence came to light.

In this case, LB1's humerus was discovered in 2004, and it was confirmed that this individual was indeed generally tiny, so it was not a case of microencephaly.

They also discovered a second jaw and more body parts from eight other individuals.

And all of this pointed to the whole species being tiny, not just LB1.

And since then, discoveries of even more individuals have strengthened the argument.

Adding yet another layer of support for team tiny species, researchers have discovered remains from at least three different individuals of another small hominin species from around the same time period in the Philippines.

This new species is called Homo luzonensis, and while we're pretty sure they were pretty tiny, we can't say for sure exactly what size they were because of how fragmented the specimens are.

And we don't have any of their skulls, so we can't say anything about their brain volume.

But still, it's evidence of another short homo species living in Asia around the same time.

So assuming that Homo floresiensis as a species were really that little, there are really two different hypotheses for why.

One idea is that at some point, a bunch of small hominins landed on Flores and made it their home.

The other idea is that it was a bigger species that came to the island, and then, over time, they shrunk.

In other words, were they always small, or did something make them small?

Not like a curse or something, like evolutionarily.

That question of why they are so small would be easy to answer if we knew how big their ancestors were.

But that requires knowing who their ancestors were.

And we don't know that!

Homo floresiensis's size is not the only unusual thing about them.

They also have a weird mix of modern and archaic features.

Their skull and face shape is pretty similar to Homo erectus, just smaller.

But their hands, feet, and shoulders look more like much, much older species.

And so, it is possible that their ancestors were Homo erectus, and then they went through an evolutionary process called insular dwarfism.

Insular dwarfism is a fairly common phenomenon where species shrink when they are isolated on islands because of limited access to resources.

In fact, our floresien friends have been found with Stegodon florensis, a species of elephant that's only about 70% of the size and 30% of the weight of their mainland ancestors.

But this process often results in the smaller animals having juvenile characteristics like size while still having larger heads, which these fossils do not.

So it could be that Homo floresiensis descended from an ancient population of hominins that got to Asia before Homo erectus did, possibly some relative of Homo habilis or even an australopith.

Which would turn a lot of what we thought we knew on its head.

Like, all of the evidence we have says that Homo erectus was the first species to reach Asia about 1.6 million years ago.

So if Homo floresiensis has descended from something older than Homo erectus, that would suggest there was an even earlier migration of hominins out of Africa.

And archaeologists have actually hypothesized that it was Homo erectus's long legs that made it possible for them to even reach Asia, because having long legs allowed them to cover more ground and spread out geographically.

Unfortunately, the fossil record just hasn't given us enough to work with to say with any certainty.

We have remains from Homo erectus from around a million years ago, about 1,200 kilometers away on the island of Java.

But they're not little, and there's not much evidence to tie them directly to the hobbits.

But while the Homo floresiensis fossils themselves date to around 60,000 years ago, we've also found stone tools there that have been dated as far back as 190,000 years.

And someone had to have made them, so we can say that someone had to have been living on that island 190,000 years ago.

But between Homo erectus on Java and tools on Flores, there are 800,000 years of question marks.

And the only way to fill those gaps is with more fossils.

But first, a quick break.

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About needing more fossils, I have some good news.

In 2016, a team of researchers announced that they had found much, much older remains in a different cave on Flores called Matamenge.

They found teeth and a jawbone that dated to 700,000 years ago.

The jawbone was tiny, even tinier than the remains from the Liangboa cave.

But the jaw definitely came from an adult, because their wisdom teeth had already erupted.

Plus, it has a similar shape to a Homo erectus jaw, which meant that there was an even clearer link between Homo erectus and Homo floresiensis.

Which is exciting.

But there's only so much you can tell from a jaw and a couple of teeth.

So while more data is always good, we still don't know anything about their body or brain sizes and shapes, or how they relate to erectus and floresiensis and any other potential ancestors.

Then, in 2024, the team announced that they had found more fossils in the cave, this time an arm bone, specifically a humerus.

This humerus is definitely from an adult, and it is between 9 and 16 percent smaller than the one belonging to LB1.

It has a shape more similar to Homo erectus than any of the australopiths.

And the teeth that they found are also way more similar to erectus than Homo habilis.

The similarities to Homo erectus means that these finds support the idea that not only were Homo floresiensis not pathological, they are likely descendants of Homo erectus that ended up on the island and shrank down between a million and 700,000 years ago.

But there are still a lot of questions.

After all, we only have one skull, so we can only really confirm that the whole species' bodies and jaws were small, and we can't really say anything about their brain volume.

And it's possible that the Matamangue specimens aren't actually the ancestors of the Liangboa specimens.

We don't have anything that directly connects the two caves, and 600,000 years leaves a lot unaccounted for.

But these new fossils fill in some major gaps, which could someday help us completely solve the mystery of our mini-cousins.

So when it comes to hobbits, we have a lot more information than we did back in 2003 when I first got excited about this.

But there is still a lot more to dig into.

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