Date:

New study finds evolution of brain and tooth size were not linked in humans

A new study from the George Washington University’s Center for the Advanced Study of Human Paleobiology (CASHP) found that whereas brain size evolved at different rates for different species, especially during the evolution of Homo, the genus that includes humans, chewing teeth tended to evolve at more similar rates.

The finding suggests that our brains and teeth did not evolve in lock step and were likely influenced by different ecological and behavioral factors.

- Advertisement -

This research challenges the classically accepted view that reduction of tooth size in hominins is linked with having a larger brain. The reasoning is that larger brains allowed hominins to start making stone tools and that the use of these tools reduced the need to have such large chewing teeth. But recent studies by other authors found that hominins had larger brains before chewing teeth became smaller, and they made and used stone tools when brains were still quite small, which challenges this relationship.

The new study evaluates this issue by measuring and comparing the rates at which teeth and brains have evolved along the different branches of the human evolutionary tree.

“The findings of the study indicate that simple causal relationships between the evolution of brain size, tool use and tooth size are unlikely to hold true when considering the complex scenarios of hominin evolution and the extended time periods during which evolutionary change has occurred,” said Aida Gómez-Robles, lead author of the paper and a postdoctoral scientist at GW’s CASHP.

To conduct the research, Dr. Gómez-Robles and her colleagues analyzed eight different hominin species. The researchers identified fast-evolving species by comparing differences between groups with those obtained when simulating evolution at a constant rate across all lineages, and they found clear differences between tooth evolution and brain evolution. If the classical view proposing co-evolution between brains and teeth is correct, they expected to see a close correspondence between species evolving at a fast rate for both traits. The differences they observed indicate that diverse and unrelated factors influenced the evolution of teeth and brains.

- Advertisement -

“Once something becomes conventional wisdom, in no time at all it becomes dogma,” said Bernard Wood, university professor of human origins at GW and a co-author of the paper. “The co-evolution of brains and teeth was on a fast-track to dogma status, but we caught it in the nick of time.”

The research published Jan. 2 in the Proceedings of the National Academy of Sciences.

GEORGE WASHINGTON UNIVERSITY

- Advertisement -
spot_img
Mark Milligan
Mark Milligan
Mark Milligan is multi-award-winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 7,500 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education, the BCA Medal of Honour, and the UK Prime Minister's Points of Light Award.
spot_img
spot_img

Mobile Application

spot_img

Related Articles

Stone box containing rare ceremonial offerings discovered at Tlatelolco

Archaeologists from the National Institute of Anthropology and History (INAH) have discovered a stone box containing ceremonial offerings during excavations of Temple "I", also known as the Great Basement, at the Tlatelolco archaeological zone.

Excavation uncovers traces of the first bishop’s palace at Merseburg Cathedral Hill

Archaeologists from the State Office for Monument Preservation and Archaeology (LDA) Saxony-Anhalt have uncovered traces of the first bishop’s palace at the southern end of the Merseburg Cathedral Hill in Merseburg, Germany.

BU archaeologists uncover Iron Age victim of human sacrifice

Archaeologists from Bournemouth University have uncovered an Iron Age victim of human sacrifice in Dorset, England.

Archaeologists find ancient papyri with correspondence made by Roman centurions

Archaeologists from the University of Wrocław have uncovered ancient papyri that contains the correspondence of Roman centurions who were stationed in Egypt.

Study indicates that Firth promontory could be an ancient crannog

A study by students from the University of the Highlands and Islands has revealed that a promontory in the Loch of Wasdale in Firth, Orkney, could be the remains of an ancient crannog.

Archaeologists identify the original sarcophagus of Ramesses II

Archaeologists from Sorbonne University have identified the original sarcophagus of Ramesses II, otherwise known as Ramesses the Great.

Archaeologists find missing head of Deva from the Victory Gate of Angkor Thom

Archaeologists from Cambodia’s national heritage authority (APSARA) have discovered the long-lost missing head of a Deva statue from the Victory Gate of Angkor Thom.

Archaeologists search crash site of WWII B-17 for lost pilot

Archaeologists from Cotswold Archaeology are excavating the crash site of a WWII B-17 Flying Fortress in an English woodland.