For the first time, an interdisciplinary team of scientists has identified two genes that influence the shape of the skull of modern man – and they are from the Neanderthals.
"Billions of people living today carry a small portion of the Neanderthal genes in their genome – a distant echo of mingling when our ancestors left Africa and met Neanderthals," said study author Philipp Gunz, a paleoanthropologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, via e-mail.
These are typically people with a European background who originate from crossings between Neanderthals and modern Europeans.
"By combining data from fossils, genetics and brain scans, we can learn something about evolutionary changes in brain development in our own species," Gunz said.
The team used MRI scans to analyze the skull shape of the brain of about 4,500 people before they looked at their genomes to find out which fragments of Neanderthal DNA they were carrying.
They also studied fossil skulls and ancient genomes to calculate the shapes of Neanderthal and modern human skulls for comparison, and then examined whether certain specific genes in the people they were carrying were linked to less spherical brains.
They found two gene variants that have a subtle effect on the skull shape, on chromosomes one and 18, which according to the research cause major disruptions to brain development if they are disturbed.
"It gives us our first glimpse of how genes can contribute to this particularly striking aspect of the anatomy of our species," said director of the Max Planck Institute for Psycholinguistics, which also led the research.
The gene variants on chromosomes one and 18 are linked to the expression of two nearby genes called UBR4 and PHLPP1 that influence the formation of new nerve cells and their isolation.
"We would like to know more about globularity because it can relate to specific changes in the way our brains are organized – the relative size of different parts of the brain and how they are connected to each other, compared to our ancestors."
But Fisher wants to emphasize that the research does not mean that people with an elongated skull have more Neanderthal DNA, nor can behavior be explained by the shape of the skull. Instead, the team searched for the effect of cranial boltality on the distinctive brain biology of modern humans.
Gunz told CNN that there are potential links between evolutionary changes in skull form and brain areas involved in the preparation, learning and coordination of movements, as well as cognitive functions such as memory, attention, planning and possible speech and language evolution.
"This is certainly an important study, showing how fragments of Neanderthal DNA have a direct effect on people's brain shape (and presumably brain function) today," said Professor Chris Stringer, a paleoanthropology specialist at the Natural History Museum in London, who was not involved in the investigation.
"The research shows that the evolutionary change in a spherical shape of the brain in modern man (and reflected in a more spherical brainteaser in fossils) was rather a complex multi-step process than a simple switchover," he added.
The latest study builds on previous research that has improved our knowledge of our human origins.
Although these Neanderthal genes are believed to stimulate brain regions that allow us to visualize objects and use devices, the researchers say that this development is at the expense of a cognitive deficit that can explain schizophrenia and autism-related disorders. .
In 2018, researchers dispelled the myth that Neanderthals lived more dangerous and violent than humans, and in another study CT scans of fossils were used to reveal that Neanderthals might not fit into the body and bowed position of the barrel in museums and study books.
CNN & # 39; s Ashley Strickland and Meera Senthilingam have contributed to this report.