The chicken. Sorry to break the suspense in the egg (and sorry for the joke), it’s useless to hide it, especially when you don’t have any explanation for this answer (which is the whole purpose of this document).
So, why this question? This dilemma is as old as the philosophy itself (back to the 4th century BC). It intends to point the futility of searching for a beginning or an end to a circular causality relation: the chicken came from the egg; the egg came from the chicken. Apparently, this philosophical view hasn’t remained through ages, because humans love answering big questions. Even if it is not their purpose.
Until now, we thought it would be the egg. Stephen Hawking, one of the biggest genius of our time, argue that the chicken as we know is a simple mutation from another species, and like all mutation it happens only on the next generation, which came from an egg. Problem solved. Apparently.
But, in the summer of 2010, two British researchers found the true answer: it is called ovocledidin-17. Behind this strange name is hidden a protein, the protein that controls eggshell crystallization. Without this protein, an egg cannot be formed. And this protein can only be found on chicken’s ovaries. As a result, the “first egg” could only be created by the first chicken.
To continue the story, these two researchers weren’t trying to solve this problem at the first place. The idea was to capture all CO2 excess a car or another pollutant device, imprison this excess into an eggshell, and store it to be re-used later. The structure of the egg was studied because of his weight and sealing capability.