New look at lampreys rewrites textbooks on origins of sympathetic nervous system

Sympathetic neurons pepper the embryos of the jawless fish—Earth’s first vertebrates—and overturn the idea that “fight or flight” was an innovation of jawed vertebrates.

Sympathetic neurons pepper the embryos of the jawless fish-Earth's first vertebrates-and overturn the idea that "fight or flight" was an innovation of jawed vertebrates.