Newborns 'have the brains of a caveman'
THE brains of newborn babies are about the same size and of similar appearance to those of Neanderthals, but alter in the first year of life, a new scientific study has suggested.
The differences between our brains and those of our extinct relatives take shape mainly after birth and in the initial 12 months, a report in Current Biology said.
The findings are based on comparisons of virtual imprints of the developing brain and surrounding structures, called endocasts, derived from the skulls of modern and fossilised humans, including that of a newborn Neanderthal.
Dr Philipp Gunz of the Max Planck Institute for Evolutionary Anthropology, who undertook the study, said the differences researchers observed in early brain development were thought to reflect changes in the underlying brain circuitry.
It is this internal organisation of the brain that matters most for cognitive ability.
He said: "In modern humans, the connections between diverse brain regions that are established in the first years of life are important for higher-order social, emotional and communication functions.
"It is therefore unlikely that Neanderthals saw the world as we do."
Dr Gunz said the issue of whether cognitive differences exist between modern humans and Neanderthals is hotly debated in anthropology and archaeology.
Many researchers had assumed the cognitive capabilities of the two species were similar because the range of brain sizes in Neanderthals overlaps with humans. The new findings challenge that notion.
The elongated overall shape of the braincase has not changed much in the course of more than two million years of human evolution, despite a big increase in endocranium volume.
It is the globular braincases of modern humans that distinguish us from our closest fossil relatives and ancestors.
The new findings show that, at the time of birth, both Neanderthals and modern humans have elongated braincases, but only modern human endocasts change to a more globular shape in the first year of life.
The team had earlier found the developmental patterns of chimpanzee and human brains are remarkably similar after the first year of life, but differ markedly immediately after birth.