Homo naledi is an extinct species of archaic human that lived in southern Africa about 250,000 to 300,000 years ago. For reference, 300,000 years ago is about when our species, Homo sapiens, is believed to have first appeared.
Homo naledi was only discovered by paleontologists in 2013, with the species' fossilized remains found in a deep and complex cave system known as Rising Star. They were small, averaging 4 feet 9 inches (143cm) in height, with small brains just over a third the size of ours.
Paleoanthropologist Lee Berger has been studying the Rising Star cave system, and has recently announced startling conclusions that have rocked the field. He reports that despite their ape-sized brains, Homo naledi engaged in very complex behaviors thought to be the sole providence of modern humans. Homo naledi:
- Used fire to explore and utilize the caves, and to cook animals;
- Buried their dead; and
- Marked the graves with art engraved on the cave walls
Some experts are not convinced, and say that the evidence of such sophisticated cultural and symbolic behaviors could have been left by Homo sapiens who used the caves long after Homo naledi became extinct. Dr. Berger's studies are currently under peer review.
From the New York Times article:
If the researchers are right, the findings will challenge some of the most important assumptions about human evolution. Humans and Neanderthals have huge brains compared with those of earlier hominins, and paleoanthropologists have long assumed that the bigger size brought major benefits. There would have to be some upside to outweigh the problems, evolutionarily speaking, of having big brains. They require a lot of extra calories to fuel, and an infants' large heads put mothers at risk of dying during childbirth.
One benefit of a big brain might be complex thinking. Neanderthals have left behind an impressive record of cooperative hunting, tool use and other skills. And modern humans make symbols, use language and perform other feats of brainpower.
If a hominin like Homo naledi could make engravings and dig graves, it would mean brain size was not essential to complex thought, said Dietrich Stout, a neuroscientist at Emory University who was not involved in the studies.
National Geographic has an article with plenty of photographs, charts and illustrations, link here.
Lee Berger, in the ABC News video below:
One of the biggest impacts of this research is that it erases the idea of human exceptionalism based on our big brain. We have sat for hundreds of years, trying to justify why humans are different than animals, why we are special in the world. But Homo naledi just taught us that it's not about that big brain, nor are we that exceptional, nor did we likely do these things first — others did them. And so, all of those are going to have profound impact not just on our study of Homo naledi, but on our view of ourselves in nature.
