The human brain is not a single organ, but two separate systems that evolved independently before fusing together, according to groundbreaking new research. … Armed with the knowledge of how hindbrain cells uniquely form, the team has successfully turned human stem cells into becoming functional hindbrain motor neurons in a lab for the first time.
Maybe I’m too sleep deprived, but why does “built from two blueprints” equal “is two organs”? When the two base components fuse they become one self-contained unit.