Does human intelligence come from our big brains? A new discovery in ancient humans with brains one-third the size of ours is challenging the idea that bigger is better.

Does human intelligence come from our big brains? A new discovery in ancient humans with brains one-third the size of ours is challenging the idea that bigger is better.

NEW YORK — Fossil remains of the species — named Homo naledi — were uncovered in underground caves in South Africa a decade ago.

Now researchers claim they have found evidence of the species’ complex behaviors, such as burying dead bodies and carving symbols on cave walls. This behavior has been observed only in animals with larger brains.

The findings are surprising for a creature with so small a brain.

“”We’re facing a fascinating discovery,” said Lee Berger. He led research that was funded by National Geographic Society where he currently works.

The Homo naledi species is still new and mysterious

H. naledi is a pretty new addition to the family tree of hominins, which includes our direct ancestors and other extinct relatives who walked on two legs.

Berger and his team announced the species in 2015, after a tip from local spelunkers led them to the Rising Star cave system near Johannesburg where they uncovered fossils from at least 15 individuals who lived around 300,000 years ago.

These creatures shared some characteristics with modern humans. For example, they had legs designed to walk upright, and their hands could manipulate objects. This was according to John Hawks of University of Wisconsin Madison, an anthropologist who is a part of the research group.

But other features looked more ancient, including their small brains.

Researchers returned to ancient caves for a closer look

In recent years, team members have ventured back into the caves, a tricky descent through tight underground spaces. They reported that what’s below shows the species from a different perspective.

A new study describes what the researchers believe were intentionally buried sites. In shallow pits in the earth, they found fossilized remains of children and adults in a fetal posture.

Another study describes a series of marks carved into the cave walls, including geometric patterns and cross-hatched lines.

“This takes time and energy to accomplish,” Berger said, the researcher who conducted the original research at the University of the Witwatersrand.

All of this behavior would be surprising for a creature whose brain was closer in size to an ape’s than a human’s, experts said.

Brain size may not be as important as we thought

Decades ago, we thought Homo sapiens were the only ones who could figure out how to use fire, bury their dead or create art, said Chris Stringer, a human evolution expert at London’s Natural History Museum who was not involved in the research.

Since then, we’ve learned that other groups like Neanderthals also lived complex lives. But those species still had big brains — unlike H. naledi, whose burials would raise further questions about human evolution, Stringer said.

For Agustin fuentes, a Princeton University anthropologist and study author, H. naledi’s evidence shifts the emphasis away from brain size. Fuentes stated that “big brains still matter.” “They just don’t explain what we thought they explained.”

More research is necessary to confirm the team’s conclusions

Scientists haven’t yet been able to identify how old the engravings are. So the current evidence can’t say for sure whether H. naledi was truly the one to create the symbols, or if some other creature — maybe even H. sapiens — made its way down there at some point, said Rick Potts, director of the Smithsonian’s Human Origins Program who was not involved in the research.

Berger and colleagues describe their findings in studies posted online Monday. Some outside scientists believe that more research is required to question what we think about the evolution of complex human thinking. The study hasn’t been peer reviewed yet.

“There’s still a lot to uncover,” Potts said.

The post Does human intelligence come from our big brains? The idea that larger is better is being challenged by a new discovery of ancient human brains with a third the size. was first published on Business Insider .