Geoffroy St. Hilaire Was Right

Back in the 19th century, Geoffroy St. Hilaire proposed that vertebrates and most invertebrates were inverted copies of each other. Vertebrates have a dorsal nerve cord and ventral heart, while an insect has a ventral nerve cord and dorsal heart. It was an idea that was dismissed at the time, but the latest advances in molecular biology seem to prove that he was actually right. PZ Myers has the full fascinating story over at Pharyngula.