Brain Development Differs between Neanderthals and Modern Humans

The closest living ancestors of contemporary humans are neanderthals. Thus, making comparisons with them can reveal intriguing details about what distinguishes Modern Humans from earlier species, such as how the brain has evolved. The mammalian neocortex, the greatest portion of the brain’s outer layer, is essential for many cognitive functions. It had a tremendous expansion throughout the period of human development in the species that gave rise to both Neanderthals and, resulting in brain sizes that were comparable between the two species.

The differences between the Neanderthal and Modern Humans brains in terms of their development and functionality, on the other hand, are mostly unknown. Researchers from the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Leipzig and the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) in Dresden have now found that Modern Humans spend more time than Neanderthals preparing their neural stem cells’ chromosomes for division.

These cells are the cells from which neurons in the developing neocortex derive. In contrast to Neanderthals or chimpanzees, Modern Humans experience fewer mistakes when chromosomes are distributed to daughter cells, which may have an impact on how the brain grows and works. According to this study, contemporary people and Neanderthals developed their brains differently on a molecular level.

About one hundred amino acids, the building blocks of proteins in cells and tissues, altered in Modern Humans when their ancestors diverged from those of Neanderthals and Denisovans, their Asian relatives. This shift extended to practically all modern people. These alterations’ biological relevance is mainly unclear. However, three proteins that are essential in the distribution of chromosomes, the genetic information carriers, to the two daughter cells during cell division, underwent six of those amino acid alterations.