Science Natural Science Finally Answered! Which Came First, the Chicken or the Egg? The granddaddy of causality dilemmas has a solution, and we have the simple science to explain it. By Melissa Breyer Melissa Breyer Twitter Editorial Director Hunter College F.I.T., State University of New York Cornell University Melissa Breyer is Treehugger’s editorial director. She is a sustainability expert and author whose work has been published by the New York Times and National Geographic, among others. Learn about our editorial process Updated March 18, 2022 Share Twitter Pinterest Email Treehugger / Christian Yonkers Science Space Natural Science Technology Agriculture Energy Which came first, the chicken or the egg? The chicken, no, the egg, no, the chicken, no, the egg. It's enough to make your head spin right off your neck. We've all been through the logic; most of us end up at the same place. As Luna Lovegood, the dreamy yet dotty witch from Harry Potter put it when asked the riddle, "A circle has no beginning." And indeed, attempting to identify the first case of a circular cause and consequence is an exercise in utter futility. For those who don't have a pat story involving a divine being who turns out perfectly formed species, it's a no-win situation. Even the Greek-Roman philosopher Plutarch couldn't exactly come up with a solution. He went with the decidedly non-answer answer that the egg was first as “it begets and contains everything” ... and also that the chicken was first because in the beginning, creation was “vigorous and perfect," and "self-sufficient and entire.” Treehugger / Christian Yonkers But that doesn't stop us from asking. Luckily for people kept awake at night by such quandaries, NPR's Robert Krulwich got to the bottom of the dilemma when he, thankfully, stumbled across the video below. Basically, many, many moons ago there was a chicken-like bird. It was genetically close to a chicken but wasn't a full-blown chicken yet. The video calls it a proto-chicken. So proto-hen laid an egg, and proto-rooster fertilized it. But when the genes from ma and pa almost-chicken fused, they combined in a new way, creating a mutation that accidentally made the baby different from its parents. Treehugger / Christian Yonkers Although it would take millennia for the difference to be noticed, that egg was different enough to become the official progenitor of a new species, now known as ... the chicken! So in a nutshell (or an eggshell, if you will), two birds that weren't really chickens created a chicken egg, and hence, we have an answer: The egg came first, and then it hatched a chicken. Treehugger / Christian Yonkers Maybe the question we should really be asking is: Which came first, the proto-chicken or the proto-chicken egg?