Before the Hobbits There Were Smaller Hobbits

In a landmark discovery on the Indonesian island of Flores, scientists have found bones from tiny hominins that pre-dated the famous hobbit by 600,000 years.

On September 2nd, 2003, a team of researchers led by Mike Morwood unearthed an incredible skull on the Indonesian island of Flores. It was very small, like that of a child. But its permanent teeth and other features revealed that it belonged to an adult—a 30-year-old female who stood just 3.5 feet tall, weighed just 55 pounds, and had a chimp-sized brain. The team called her LB1 after Liang Bua cave where she was found, and they agreed that she belonged to a new species: Homo floresiensis.

The rest of the world would know her and her kin by the nickname Morwood gave them: the hobbits.

The team have since recovered the partial skeletons of nine hobbits, and their latest estimates suggest that these diminutive hominins lived on Flores between 50,000 and 100,000 years ago. Why were they so small (more on that later)? And where had they come from? Right from the off, Morwood believed that there must be more hominins on Flores—older fossils that would attest to the hobbit’s origins. They just had to find them.

The So’a Basin, about 46 miles east of Liang Bua, seemed a likely site. Archaeologists had been digging there since the 1950s and had uncovered many stone tools—but never any hominin fossils. In the 1990s, Morwood’s team set to work at the basin, at a site called Mata Menge. They started small, but by 2010, the team of a few dozen scientists and excavators had ballooned into a hundred-strong workforce. “We were slowly chiseling through concrete-like rock, and the fossil basins cover a very large area,” says Adam Brumm, who had joined the team as a graduate student in 2004. “It was like looking for a needle in a thousand haystacks.”

Over the years, the team unearthed some 20,000 fossils, but all belonged to rodents, Komodo dragons, or dwarf elephants. They found stone tools in their thousands, but never any sign of the tool-makers. Had the dragons just annihilated the fragments? Were they just desperately unlucky?  “In Africa, there are hominid fossils practically raining from the sky,” says Brumm. But in Flores: nothing.

Then, on 8th October 2014, the penultimate week of the project’s last year, they finally hit paydirt. Supervisor Mika Puspaningram was looking through the day’s haul when she saw what was clearly a human tooth. It had come from a layer of sandstone that, in quick succession, yielded five more teeth and a jaw fragment, from at least three different people. The specimens are small in size and few in number, but they have a big story to tell.

They’re around 700,000 years old, which makes them 10 times as old as the hobbit. Based on their shapes, it seems likely that they belonged to the  great-great-great-etc-grand uncles and aunts of the Liang Bua hobbits, and were part of the same species—Homo floresiensis. “It’s like the ancestor of the hobbit… is the hobbit,” says Brumm.

But oddly, the Mata Menge individuals were even smaller. The jawbone, which probably came from an adult, is between 21 and 28 percent shorter than those from Liang Bua. “Is the Liang Bua hobbit a bigger version of its ancestor? It’s extraordinary to think,” says Brumm. Perhaps the Mata Menge specimens just represented the smaller end of hobbit sizes. Perhaps they were all women, and smaller than the men. “We really don’t know. But at this stage, it’s possible that the hobbit was a giant in one sense.”

One thing is clear: the hobbits could not possibly have been modern humans, whose growth was stunted by a disorder like microcephaly or Down’s syndrome. To most researchers who have worked on the hobbits, those hypotheses were already dying, but “these new finds put a huge spike in the coffin,” says Dean Falk from Florida State University. At 700,000 years old, the Mata Menge hobbits are older than early modern humans. They were in Flores before Homo sapiens had even left Africa.

That leaves two possible explanations about their origins. The most widely accepted is that they were the dwarfed descendants of Homo erectus, the same upright, tool-wielding, big-brained, globe-trotting hominin that gave rise to us. The underdog alternative is that the hobbits descended from some earlier hominid, perhaps a smaller version of Homo habilus or an Australopithecus who migrated out of Africa before Homo erectus.

Many members of the Mata Menge team are convinced that the “dwarfed erectus” idea is right, based on distinguishing traits on the teeth they uncovered. “I remain skeptical,” says William Jungers from Stony Brook School of Medicine, who examined casts of the new fossils last month. He predicts that when the team finally finds million-year-old hominin fossils from Flores, “they'll already be small-bodied and more primitive than H. erectus.” Falk is on the fence. The new evidence doesn’t rule out Jungers’ idea, she says, but it makes it clear that the dwarfed erectus hypothesis “is more viable than some have thought.”

The stone tools of Flores add to the mystery. The Mata Menge team found 47 artifacts in the same sandstone layer that yielded the jaw and teeth. These are very similar to much younger tools from Liang Bua, which suggests that the tiny people of Flores had undergone a period of cultural stasis that lasted hundreds of thousands of years.

It wasn’t always like that. In 2010, Brumm and his colleagues found stone tools on Flores that were a million years old. “The technology is similar, but we have a type of large, robust, carefully flaked tool that does not appear in the younger levels and isn’t found in association with the younger hominids,” says Brumm. “If you found it in Africa, you’d call it an Acheulean pick—a kind of hand-axe. These tools have been associated with advanced cognition.”

Kinez Riza

So perhaps a population of large-bodied Homo erectus arrived in Flores a million years ago and brought their advanced tools with them. Islands are weird crucibles of evolution, where constrained space, scarce resources, and absent predators tend to drive small animal to very big sizes (like Galapagos tortoises or Komodo dragons) or big ones to very small sizes (like dwarf elephants). The Flores arrivals went in the latter direction. In just a few hundred millennia, their bodies shrank and, for reasons that are still unclear, their technology simplified. They transformed into the hobbits.

It’s a nice story but as Brumm stresses, “We just need more evidence.” The team is now going to extend their excavation into the mountainside, searching in the same sandstone layer where the teeth and jaw came from. They want to find more remains from the Mata Menge hobbits, and perhaps fossils of the even older hominins that were associated with those advanced million-year-old tools. “Somewhere on this island will be the form that gave rise to the hobbit,” says Brumm. “That’s what we need to find.”

Morwood, sadly, will not be involved. He died of cancer in July 2013. “It was a tragic thing,” says Brumm. “He was out there every step of the way. He was out there, body riddled with cancer, in the punishing heat of the site. He died months before we found the specimens. But he was there in spirit. Mike was deeply respected by the people there, the Nage, and the elders were devastated by his loss. They believe that Mike’s spirit is still there on the island, still searching for hominid fossils. And that he’s happy.”