alt Hacker NewsI'm not sure if this is intended as serious or tongue-in-cheek.
Obviously parents come before offspring.
The earliest form of reproduction is just binary fission - what an amoeba does by splitting itself into two. In it's simplest (origins of life) form this is just a mechanical process of a proto-metabolism (bunch of chemicals) being split into parts that are smaller versions of the "parent", e.g. some proto-cell composed of seashore froth being whipped into smaller versions of itself.
Eventually the division process became asymmetrical with the spawned child being a simpler proto-version of the adult, capable of then independently developing into the adult form. It seems life developed in the oceans before emerging onto land, so the history is probably of multi-cellular fish-precursors reproducing by spawning simpler (conceptually egg-like) versions of themselves, eventually evolving into egg-laying fish, and then egg-laying land-based animals including the dinosaurs from which birds developed.
So, maybe the best answer to "which came first, chicken or egg?" is "fish".
I'm glad you couldn't tell! It's basically tongue in cheek, as the question is silly to begin with.
And of course eggs predate chicken, eggs are seriously old technology.
Back to the tongue in cheek: there is something easily tautological that chickens come from eggs. At some point a non-chicken laid an egg, and the first chicken was born from it. This is true regardless of which mutation one decides is "the" mutation that makes for the "first" chicken.
QED it's the egg