"The Evolutionary Impact of an Ancient Virus on Brain Complexity"

A study published in Cell suggests that complex nervous systems in vertebrates, including humans, may have arisen from ancient viral infections that inserted genetic code into their genomes. The inserted code helped produce myelin, a protective sheath around nerve cells that speeds up signal transmission, enabling the evolution of complex neural networks. This viral DNA, comprising about 8% of the human genome, has been repurposed for various functions, including forming the placenta and regulating hormone levels. The process of infection, repurposing, and transformation continues, highlighting the dynamic nature of evolution.