The Chicken Or Egg Debate Is Finally Resolved By Scientists
People have been arguing about which came first—the chicken or the egg—for centuries. It’s a simple question on the surface, but because you need a chicken to lay an egg and an egg to hatch a chicken, the answer feels trapped in a loop.
This question goes back at least as far as ancient Greece. Around 100 AD, the philosopher Plutarch wrote about it without coming to a definitive conclusion. Since then, it has become one of those enduring riddles that pop up in casual conversation, classrooms, and scientific discussions alike.
In recent years, scientists have stepped in with what they consider a clear answer: the egg came first. Their reasoning starts with the fact that egg-laying as a reproductive strategy existed long before chickens ever did.
Fossil evidence shows that eggs were being used by a variety of creatures more than a billion years ago. Chickens, by contrast, are a relatively new species, emerging roughly 10,000 years ago through the domestication of their wild ancestor, the red junglefowl.
Evolution explains why the egg predates the chicken. Birds evolved from reptiles, and reptiles laid eggs long before the first actual birds appeared. At some point, a bird very similar to a chicken, though not quite the modern chicken, was born from an egg laid by its reptile-like ancestor.
That egg contained genetic changes that produced the first animal we would recognize as a chicken. In this view, the egg that gave birth to that proto-chicken existed before the first chicken itself.
Chickens have existed for more than 10,000 years.
However, another perspective flips the conclusion by focusing specifically on chicken eggs rather than eggs in general. An article in New Scientist argues that the first true chicken must have come before the first true chicken egg.
According to that view, two red junglefowl mated and produced offspring with genetic mutations significant enough to be classified as the first true chicken. That bird hatched inside a junglefowl egg and later laid the first egg we would identify as a chicken egg. Seen this way, the chicken came before the chicken egg.
Getty StockBoth sides of the debate rest on solid reasoning, which is why the question still sparks discussion. If you consider eggs broadly as a method of reproduction used by countless species for hundreds of millions of years, the egg clearly came first. If you narrow the question to the first egg laid by an actual chicken, the argument can be made that the chicken came first.
Which came first: the chicken or the egg?
Ultimately, the answer depends on how you define the terms. Are you asking which came first in evolutionary history—eggs or chickens? Or are you asking specifically about the first chicken egg? There isn’t a single, universally accepted answer, but that’s what makes the question interesting rather than frustrating. It illustrates how science relies on precise definitions and how language shapes our understanding of concepts.
Getty StockSo next time someone poses the age-old riddle, you can explain both viewpoints clearly. Broadly speaking, eggs existed long before chickens, so eggs win if you’re talking about reproductive history. But if you insist on chicken-specific eggs, you could say the first true chicken came first.
Either way, the debate highlights that even the simplest questions can unlock profound insights into biology and evolution.
