Our ancient ‘hobbit’ cousins ate dragon leftovers

For over twenty years, a tiny, extinct human species found on an Indonesian island baffled scientists, in part because it seemed to live a big life. Despite their small brains, these three-foot-tall humans, appeared to craft complex stone tools, tame fire, and hunt large game. Researchers called them Homo floresiensis after the island Flores and nicknamed them “hobbits” after the unlikely heroes of J.R.R. Tolkien’s books.

Now, a new paper in the journal Science Advances knocks down a pillar of the hobbit’s once-impressive intellect. Soon after H. floresiensis was discovered in 2003 in a cave called Liang Bua, the research team had noticed scratch marks on bones were buried in the same layers of the cave floor as the hobbits’ stone tools. These remains belonged to a Stegodon, an extinct, dwarfed elephant relative roughly the size of a cow. Some saw that as evidence of a hobbit meal, though that conclusion rested almost entirely on the fact that the bones and tools turned up together.

 “I wanted to see if we really could show that H. floresiensis was the hunter that had been portrayed for decades,” says Elizabeth Grace Veatch, a paleoanthropologist at the University of Tübingen and the study’s lead author. Instead, the new analysis suggests that the planet’s largest and most terrifying living lizard—the Komodo dragon—beat the hobbits to the island’s largest prey.

(Did ancient “hobbit” humans create these million-year-old tools?)

Second breakfast or elevenses?

To test the theory of hobbit hunters, Veatch and her colleagues first had to learn to decipher the dragon's bite. At a zoo in Atlanta, the team ran a feeding experiment: After visiting hours, they turned a Komodo named Rinca loose on a goat carcass. His shearing teeth cut through the flesh and occasionally striking bone. What struck Veatch was the creature's composure. “He was careful and calculated,” she says. She then gathered the 72 remaining bones and the team set out to examine every mark under the microscope, building a reference library of the traces a Komodo leaves behind.

The team then compared those modern marks against the marks on the ancient Stegodon bones under a high-powered microscope. The dragon's tooth marks were shallow and wide, sometimes ending in a fan of striations where the tooth’s serrated edge drags. A stone tool, on the other hand, would have left a mark that’s deeper and straighter.

Once they could confidently parse the two types of scratches, the team mapped out where each fell. The dragon marks clustered around the areas with the best pieces of meat, including the shoulders and hips, suggesting they got there first. The hobbit cutmarks fell on the scraps, like the feet and ribs. “At first, I thought all I was seeing were cutmarks,” Veatch says. But she was surprised when “almost all of them turned out to be Komodo dragon tooth scores.” The hobbits, it seems, were merely scouring for whatever the dragons left behind. In that light, they seem to have lived out one of Tolkien’s own warnings: “It does not do to leave a live dragon out of your calculations, if you live near him.”

Michael Petraglia, a professor of human origins at Griffith University in Australia who was also not involved in the study, says, “the authors make a very strong and convincing case for passive scavenging.”

This distinction between hunting versus scavenging matters in human evolution, especially when it comes to big game. Taking down prey bigger than ourselves is considered a marker of intelligence because pulling it off takes cooperation, planning, and the kind of accumulated, passed-down knowledge that scientists call cumulative culture. For this reason, researchers often assume hunting was only possible for the largest-brained species, like our own (Homo sapiens) and Neanderthals (Homo neanderthalensis).

But it’s “very hard to distinguish hunting from scavenging based on bone modification features,” says Kay Behrensmeyer, a paleoecologist at Smithsonian’s National Museum of Natural History in D.C. who was not involved in the study. This difficulty leaves her not yet convinced of a “scavenging only” hypothesis for the hobbit, though she says the team’s case for identifying Komodo cutmarks and hobbit toolmarks looks convincing.

Were hobbits simpler than suspected?

The possibility that hobbits may not have been hunters is just the latest in a string of finds from ongoing excavations at Liang Bua Cave that have slowly shrunk that image of hobbit cognitive complexity over the last decade. The tools, for example, have turned out to be simpler than originally assumed, no fancier than human ancestors’ earliest toolkits. And in restudying the layers of the cave a decade ago, the team found they'd confused some of the deeper “hobbit layers” of the cave floor with occupied the cave, accidentally anointing the wrong human as the fire-maker.

“It’s now been 25 years since I started working here,” says Thomas Sutikna, the excavation director at Liang Bua, an archaeologist at Indonesia’s National Research and Innovation Agency, and one of the paper's authors. “It feels very satisfying to know that our hard work has refined our knowledge about Homo floresiensis, even if it means some of our initial interpretations turned out to be incorrect.”

The new paper also reexamined the question of fire, initially supported by charcoal and burnt animal bones at Liang Bua. A previous analysis had suggested that this evidence had come, not from the time when hobbits lived in the cave, but from younger layers of the cave floor laid down when Homo sapiens occupied the site. Of the 3,155 Stegodon bone fragments the team examined in the new study, only a single rib showed signs of fire. And that rib sat right on the seam where younger “sapiens layers” meet the older hobbit ones, threatening the same potential confusion that scrambled the earlier reading. The team thinks this bone was later scorched, in Homo sapiens times, as it sat near the surface.

The cave’s rat bones made the contrast even starker: across 4,240 rodent bones from the hobbit layers, not one was burned, compared to roughly one in five charred in the sapiens layers. Only further evidence, the researchers argue, that the hobbits weren’t so behaviorally advanced after all.

(Read more about what rat bones have taught us about the Liang Bua hobbits.)

This points to perhaps the biggest question left in the hobbits’ journey: Who did they evolve from? The larger, relatively advanced Homo erectus? Or an older, simpler human species that was already small-brained and small-bodied?

Whether the new findings tip that question depends on what you make of fire and hunting to begin with, says National Geographic Explorer Matthew Tocheri, an anthropologist at Lakehead University and a co-author on the study. If scientists accept fire and hunting as part of the Homo erectus toolkit, he adds, an idea that’s still debated, the new results weaken that argument.

Petraglia cautions against reading the ancestry story as closed, noting it’s still “unresolved.”

Hobbits were ‘hearty folk’

When the hobbit was first uncovered, the find tempted scientists with the possibility that small brains could do big things in human evolutionary history. Since then, Researchers in South Africa, for example, have controversially argued that another small-brained species, Homo naledi, behaved in advanced, symbolic ways.

But with the new hunting analysis, perhaps we’re “moving away from the surprising behavior stories,” Petraglia says, which would be “more consistent with what we know about small-brained hominins.”

(Colossal storks flew over Indonesia’s island of “hobbit”-size humans.)

Instead of asking how much brainpower certain behaviors require, then, maybe researchers should be asking how much brainpower a species needs to simply survive. After all, the hobbits were one of the last surviving human species before it became just us Homo sapiens.

“For all the new picture strips away, the hobbits were quite adaptively successful,” Petraglia says, noting they were able to survive “changing environments and challenging circumstances” for close to a million years on the island, far longer than Homo sapiens have existed on Earth.

Veatch agrees. “The fact that they survived isolated on an island until 50,000 years ago without needing to hunt or use fire to survive speaks volumes,” she says. It’s a testament, she thinks, to how well they adapted to their own strange corner of the world.

After all, while the real hobbits might not be the action stars of this adventure, they did seem to know a thing or two about living with dragons.