Neanderthals are the closest relatives to modern humans. Comparisons with them can therefore provide fascinating insights into what makes present-day humans unique, for example regarding the development of the brain. The neocortex, the largest part of the outer layer of the brain, is unique to mammals and crucial for many cognitive capacities. It expanded dramatically during human evolution in species ancestral to both Neanderthals and modern humans, resulting that both Neanderthals and modern humans having brains of similar sizes. However, almost nothing is known about how modern human and Neanderthal brains may have differed in terms of their development and function. [1]

Figure 1. Brain development differs between Neanderthals and modern humans

Figure 1 shows Researchers from the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) in Dresden and the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Leipzig have now discovered that neural stem cells -- the cells from which neurons in the developing neocortex derive -- spend more time preparing their chromosomes for division in modern humans than in Neanderthals. [2]

The effects of the modern human variants on brain development

To investigate the significance of these six changes for neocortex development, the scientists first introduced the modern human variants in mice. Mice are identical to Neanderthals at those six amino acid positions, so these changes made them a model for the developing modern human brain.“Our study implies that some aspects of modern human brain evolution and function may be independent of brain size since Neanderthals and modern humans have similar-sized brains. The findings also suggest that brain function in Neanderthals may have been more affected by chromosome errors than that of modern humans,” summarizes Wieland Huttner, who co-supervised the study. Svante Pääbo, who also co-supervised the study, adds that “future studies are needed to investigate whether the decreased error rate affects modern human traits related to brain function.”[3]

References:

1. https://phys.org/news/2022-07-difference-brain-differs-neanderthals-modern.html
2. https://www.sciencedaily.com/releases/2022/07/220729173145.htm
3. https://www.eurekalert.org/news-releases/959605

Cite this article:

Thanusri swetha J (2022), Brain development differs between Neanderthals and modern humans, Anatechmaz, pp.181