What came first the chicken or the egg?

The chicken, but the answer came from the egg.

Researchers at the University of Warwick and the University of Sheffield answered the question with the discovery that a protein produced by chickens called ovocledidin-17 (OC-17) is the key to the speedy formation of chicken eggs.

OC-17 causes the eggshell to form literally overnight by acting as a catalyst for calcium carbonate particles to transform into “calcite crystallites”. Once the crystal nucleus is large enough to grow on its own OC-17 drops off so it can kick start crystallization somewhere else.

"Understanding how chickens make eggshells is fascinating in itself but can also give clues towards designing new materials and processes.” said Professor Harding, from the University of Sheffield´s Department of Engineering Materials. “Nature has found innovative solutions that work for all kinds of problems in materials science and technology – we can learn a lot from them."