Ancient Taung Child's Brain Not Human-Like in CT Scans

It turns out that a specimen discovered in Africa about 90 years ago, called the Taung Child, may not have the human-like brain that scientists once thought. Using the latest technology, researchers have found that the hominin may not have the same infant brain development in the prefrontal region similar to that of modern humans.

The Taung Child has both historical and scientific importance as the first and best example of early hominin brain evolution. In fact, researchers have theories that it exhibits key cranial adaptations found in modern human infants and toddlers. Now, though, scientists have finally tested those theories.

The researchers performed an in silico dissection of the Taung Child with high-resolution computed tomography. Then, they compared it with the existing hominin fossil record and chimpanzee variation.

"A recent study has described the roughly 3 million-year-old fossil, thought to have belonged to a 3 to 4-year-old, as having a persistent metopic suture and open anterior fontanelle, two features that facilitate post-natal brain growth in human infants when their disappearance is delayed," said Kristian Carlson, one of the researchers, in a news release.

In fact, physical evidence does not incontrovertibly ink features of the Taung skull to early prefrontal lobe expansion. This brain region is linked to many human behaviors. Because the Taung Child doesn't possess these features, scientists now wonder whether these structures were selectively advantageous in hominin evolution, particularly in australopiths.

The findings reveal a bit more about this ancient specimen and, consequently, reveal a bit more about human evolution. More specifically, the new research reveals that this specimen is an early version of human evolution than once suspected. It also shows that there is still no evidence for this kind of skull adaptation that evolved before homo.

The findings are published in the journal Proceedings of the National Academy of Sciences.