Human Limbs May Have Evolved From Cartilaginous Fish Gills

In 1878, German anatomist Karl Gegenbaur proposed a theory that fish fins and human limbs evolved from a structure that resembles gill arches, a collection of bony "loops" in fish that support the gills.

Unfortunately, the idea was widely discounted because no fossil record was discovered to support the theory.

More than a century later though, Gegenbaur's idea is getting support. New genetic evidence has linked the evolutionary origins of the paired fins in early fish and eventually the paired limbs in mammals to the gill arches of cartilaginous fishes such as sharks, skates and rays.

In a research published in the journal Development, Andrew Gillis, from the University of Cambridge, and colleagues used the latest genetic techniques to study the embryos of the little skate and found a striking resemblance between the genetic mechanism behind the development of the gill arches and that in human limbs.

http://www.techtimes.com/articles/151790/20160420/human-limbs-may-have-evolved-from-cartilaginous-fish-gills.htm