Frog and fly genes revive the ridiculed idea that vertebrates resemble upside-down insects

摘要

The year was 1830, the place Paris, and revolutionary ideas filled the air. To most historians, that setting recalls the troubles of Charles X, the French king forced to abdicate the throne in August. But to historians of science, it evokes memories of one of the greatest scientific debates of all time-the clash between eminent French zoologists Etienne Geoffroy Saint-Hilaire and Georges Cuvier. In 1822, decades before Darwin propounded his theory of evolution, Geoffroy Saint-Hilaire wrote a provocative essay in which he linked the body plan of vertebrates such as humans to that of arthropods, a class of invertebrates that includes insects, crustaceans, and spiders. He noted that in vertebrates, some organs, such as the heart, lie in the belly, or ventral side, while other features, such as the spinal cord, reside in the back, or dorsal region.