When comparing these fossils with those of modern humans, the main difference is the elongated shape of the fossil
braincase. According to the researchers, this indicates that
brain shape, and possibly brain functions, evolved within the
Homo sapiens lineage and relatively recently.
[7][11][13] Evolutionary changes in brain shape are likely to be associated with
genetic changes of brain organization, interconnection, and development,
[17] and may reflect adaptive changes in
the way the brain functions.
[14] Such changes may have caused the human brain to become rounder and two regions in the posterior of the brain to become enlarged
during thousands of years of evolution.
[14] The Jebel Irhoud individuals also had very thick
brow ridges and lacked
prognathism.
[18]
