OK, get your “guys with tiny brains” jokes ready. Researchers have finished piecing together bone fragments found in South Africa in 2013 and determined that they came from an extinct relative of modern humans who was stuck with a tiny brain but still had the ability to talk. What good is talking if the sound keeps echoing around inside your empty skull?
Discovered in the Rising Star Cave system 50 km (31 miles) northwest of Johannesburg, the remains of Homo naledi show that this hominin could be mistaken for the proverbial missing link. Living in southern Africa between 236,000 and 335,000 years ago at close to the time the first modern humans appeared, the diminutive species had teeth that were human-sized but ape-shaped; broad apelike shoulders but small human arms and hands, although the fingers were long and strong like an ape’s. The spine was somewhat Neanderthal-like but the pelvis was shaped like that of Australopithecus afarensis – the famous 3.2 million-year-old Lucy.
Then there’s that tiny brain.
“Homo naledi’s brain seems like one you might predict for Homo habilis, 2 million years ago. But Homo habilis didn’t have such a tiny brain — Homo naledi did.”
In a new study published this week in the journal Proceedings of the National Academy of Sciences, co-author Dr. John Hawks from the Evolutionary Studies Institute at the University of Witwatersrand described the surprising new discovery about the brain of Homo naledi. While it was barely the size of an orange or a clenched fist, impressions on the inside of the skull showed that it closely resembled the shape of larger and more modern humans.
In particular, the Homo naledi had a human-like asymmetrical brain, with the left side more forward than the right, which is a sign of higher level behavioral complexity. Even more interesting, the frontal lobe was also very human-like, indicating that Homo naledi may have been able to process syntax and recognize social emotions. All of those traits are important for communication. Does this mean Homo naledi talked to their early human cousins? Co-author and Columbia University anthropologist Ralph Holloway shared his thoughts with Ars Technica.
“What exactly the span of the communicative abilities would be—there’s no way of knowing just looking at an endocast. It really does suggest that their communicative abilities probably included some rudimentary language. Certainly that’s where my speculation would go.”
Tiny brains that talk — haven’t politicians already proven this is possible?
If homo naledi could verbalize, did they make small talk with humans? Did they, like the Neanderthals and the Denisovans, then have sex with humans? Can this explain jockeys, gymnasts and flyweight boxers? No Homo naledi DNA has been found in the human genome … yet. And the fossils don’t explain why – despite human physical traits and a small but powerful brain – homo naledi went extinct, says Holloway.
“We have so little evidence. It sounds great when you say that we have this skull and that portion of the skull and so forth, but we really need an awful lot more. Our picture is very, very foggy.”
“We badly need more evidence from across the skeleton of many other hominin species. We literally know nothing about the body of Homo rudolfensis, for example. Right now, we know more about Homo naledi, Neanderthals, and modern humans than about any of the other fossil hominin species, and we’ve got to build those other samples.”
It sounds like there is good job security for a while in the field of anthropology.