“Which came first: the chicken or the egg?”
For centuries, it’s been a classic paradox, a riddle about cause and effect that’s sparked debate from ancient philosophers to Sunday brunch tables.
Originally used to express the frustration of circular reasoning, the question has taken on a new life under the microscope of evolutionary biology.
According to Darwinian theory, the answer lies in genetic mutation and natural selection. Today’s chickens evolved from non-chickens- birds that were similar but not quite the same. At some point, one of those birds laid an egg containing a mutated embryo with the DNA of what we now recognise as a chicken. So in evolutionary terms: the egg came first.
But… if you define a “chicken egg” as one laid by a chicken, the chicken has to come first. After all, only chickens lay chicken eggs- by definition.
As scientists note, it all depends on your definitions. If we’re talking about eggs in general, they existed long before chickens- and were laid by the very dinosaurs that gave rise to birds. Chickens, like all modern birds, are direct descendants of theropod dinosaurs, so in evolutionary terms, the egg quite literally came first.
So: science says egg first, but the debate lives on, in biology labs and breakfast tables alike.
📚 Source: “The egg or the chicken? An ancient unicellular says egg – Université de Genève”
Also read: What did dinosaurs actually sound like?