Research challenges old ideas on the evolution of brain size

· News-Medical

The study, published today (Tuesday, 26 November) in the journal PNAS, overturns long-standing ideas about human brain evolution. Scientists from the University of Reading, the University of Oxford and Durham University found that brain size increased gradually within each ancient human species rather than through sudden leaps between species.

The team assembled the largest-ever dataset of ancient human fossils spanning 7 million years and used advanced computational and statistical methods to account for gaps in the fossil record. These innovative approaches provided the most comprehensive view yet of how brain size evolved over time.

Professor Chris Venditti, co-author of the study from the University of ReadingThis study completely changes our understanding of how human brains evolved. It was previously thought that brain size jumps dramatically between species, like new upgrades between the latest computer models. Our study instead shows a steady, incremental 'software update' happening within each species over millions of years."

The research challenges old ideas that some species, like Neanderthals, were unchanging and unable to adapt and instead highlights gradual and continuous change as the driving force behind brain size evolution.

Dr Thomas Puschel, lead author now at Oxford University, said: "Big evolutionary changes don't always need dramatic events. They can happen through small, gradual improvements over time, much like how we learn and adapt today."

Brains, bodies, and evolutionary scale

Dr Joanna Baker, co-author from the University of Reading, said: "Why and how humans evolved large brains is a central question in human evolution. By studying brain and body size in various species over millions of years, we reveal that our hallmark large brains arose primarily from gradual changes within individual species."

Source:

University of Reading

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