It is believed that humans’ large brain feature emerged as a result of sharp leaps in development from one species to another. But scientists from Great Britain examined the largest ever dataset on fossils of ancient humans and found that the evolution of the brain happened differently.

Modern research regularly provides new information about brain development in various biological species. For example, fossils of Australopithecus Littlefoot, one of the most famous representatives of ancient man, showed how this organ evolved into a hominid. And the experiment with brain organoids of great apes —
showed that brain development in humans is determined by only one mutant gene.

Experts from the Universities of Reading and Durham (both in Great Britain) analyzed data on ancient human fossils spanning seven million years using statistical methods to eliminate gaps in the fossil record and refute long-held ideas about the evolution of the human brain. A scientific article describing the results of the study was published in the journal Proceedings of the National Academy of Sciences.

It turns out that the brain size of each ancient human species increased gradually, rather than by sudden jumps between species. If it was previously believed that Neanderthals, for example, were adaptable, it has now become clear that the driving force behind the evolution of brain size must be considered gradual and continuous changes.

“This research completely changes the understanding of how the human brain evolves. It was previously believed that brain size in different species differs significantly, as the latest computer models update. Our work shows that software is continually and gradually updated within each species, occurring over millions of years.” It shows. <…> Major evolutionary changes do not always require dramatic events. They may occur through small, incremental improvements over time, similar to how we learn and adapt today,” the paper’s authors explained.

The researchers also noted that differences in brain size seen in individual species are not always related to body size, although larger species generally have larger brains. This feature highlights that brain development over a long evolutionary period was determined by factors other than those important for individual species.