The latest discovery on Homo naledi challenges the status quo in ancient human evolution as scientists found that their pint-sized brains are capable of complex processes that rival that of modern humans.
Researchers at the University of the Witwatersrand in Johannesburg, South Africa pieced together skull fragments from the collection of fossils previously unearthed. Their discovery led them to question how the naledi survived in an environment along with other species with brains thrice bigger than theirs.
A number of similarities to the human brain were found in the naledi skulls, including the frontal lobe and the shape of the back of the brain. Other species with humanlike characteristics like Homo erectus and Homo habilis share the same trait.
The team also found that the naledi brain is asymmetrical and that the visual part at the back of the cortex is smaller than chimpanzees. These descriptions are not evident in apelike hominins like Australopithecus africanus.
"Naledi's brain seems like one you might predict for Homo habilis, two million years ago. But habilis didn't have such a tiny brain — naledi did," said coauthor and paleoanthropologist John Hawks.
Challenging The Theory Of Ancient Human Evolution
Early theories stated that the ancestors of modern humans had bigger brains which allowed them to hunt and gather. It appeared that the theory was not applicable with naledi because it had "hands well-suited for tool-making, long legs, humanlike feet, and teeth suggesting a high-quality diet."
Coauthor Lee Berger suggested that naledi's complex brain structure might mean that they may have shared some behaviors with humans. He added that this latest finding suggests that scientists may have been pursuing the wrong story that modern humans were the ones capable of producing complex tools.
The study was published May 14 in the Proceedings of the National Academy of Sciences.
Discovery Of H. Naledi
H. naledi was first announced in September 2015 after it was unearthed in the Rising Star Cave system in South Africa. Archeologists thought that the primitive hominin lived between 236,000 and 335,000 years ago.
This information is a huge breakthrough for experts because H. naledi existed at the same time Homo sapiens lived in South Africa.
"We can no longer assume that we know which species made which tools, or even assume that it was modern humans that were the innovators of some of these critical technological and behavioral breakthroughs in the archaeological record of Africa," said Lee Berger, a professor in the Evolutionary Studies Institute at Wits University. "If there is one other species out there that shared the world with 'modern humans' in Africa, it is very likely there are others. We just need to find them."