Our brain evolved from two primitive nervous systems that merged: Study

A new study suggests that the human brain evolved from two separate nervous systems that merged during evolution. Researchers at Stanford University found that the brain's two hemispheres, which are connected by a bundle of nerve fibers called the corpus callosum, were once separate entities. The study, published in the journal Neuron, used a combination of computer simulations and anatomical analysis to recreate the evolution of the human brain. The researchers found that the two hemispheres initially developed independently, with each having its own separate sensory and motor systems. As the brain evolved, the two hemispheres began to merge, with the corpus callosum forming a bridge between them. This merger is believed to have occurred around 6-7 million years ago, during the evolution of the human genus.