evolution

Our brain evolved from two primitive nervous systems that merged: Studynewscientist.com

A new study shows that the forebrain and hindbrain develop from distinct progenitor cells (OTX2‑expressing and GBX2‑expressing) in mouse, human, chicken, zebrafish and acorn worm embryos, suggesting the vertebrate brain originated from the merger of two primitive nervous systems over 550 M years ago. This insight enabled the first successful in‑vitro generation of human hindbrain motor neurons.