It’s a question that has perplexed humanity from as early as the ancient Greeks all the way to the 21st century. And we’re still dying to know:

Which came first: the chicken or the egg?

The question would be simple if we took it literally. Egg-laying animals existed far before chickens came about, so technically the egg came before the chicken. But this question, better worded as “the chicken or the chicken egg” focuses more on the cyclical cause-and-consequence, that is: “if a chicken is born from an egg, where did the egg come from?” And that a chicken, presumably, which too must have come from an egg.

So which came first?

On the one side, we have Team Chicken. Research suggests that the protein essential for the formation of chicken eggs called “OV-17″ is only found in chicken ovaries. Without it, the chicken eggshell could not be formed. So, without a chicken, you technically can’t get a chicken egg.

But this depends on the nature and the definition of a chicken egg in the first place. After all, is a chicken egg an egg laid by a chicken, or one that simply contains a chicken? Obviously the OV-17-bearing chicken had to come from somewhere. But, if an elephant laid an egg from which a lion hatched, would it be an “elephant egg” or a “lion egg”?

This leads to the other side of the story: Team Egg. During reproduction, two organisms pass along their genetic information in the form of DNA, but the replication of this DNA is never 100% accurate and often produces minor changes for the new organism. These small mutations in DNA over thousands of generations create new species. But these genetic mutation must occur in the zygote or the initial cell. So, a creature similar to a chicken, which we could call a “proto-chicken”, would have mated with another proto-chicken, and because of the small genetic mutation created the first chicken, which grew in an egg.

So the egg came first? Well, Team Chicken might argue that this is simply a chicken growing in a proto-chicken egg, however, no one mutation can ever really constitute a new species. Even though we humans like to classify all creatures into different groups and names, this is often based on how things currently are, and not how they were millions of years ago.

The process of evolution is so gradual that no one proto-chicken-to-chicken-birth could really be considered a new species at the time. Much like how dogs have come from wolves. As humans began to interact with and domesticate wolves, there was no one single point where a wolf gave birth to a dog. But rather, as particular traits came about from selective pressures such as choosing wolves that are not afraid of humans or ones that were less aggressive over many generations we can see many genetic and behavioural trait differences.

So, where does this leave us?

We’re left with two scenarios: Some early egg-laying species gradually led to the creation of the proto-chicken, which laid proto-chicken eggs. In one of these eggs, there was a mutation causing a slight change and selective advantage, and this was ultimately the first chicken, which then went on to lay chicken eggs. In this case the chicken technically came first.

Or we have a proto-chicken which gave birth to a chicken inside what we would classify as a chicken egg. As such, the egg came first.

Which brings back us to the nomenclature in question of what is a chicken egg, which is a fairly meaningless question. But the end of the day, what we can all agree on is that regardless of whether it was a chicken egg or a proto-chicken egg, the first true chicken came from an egg.

The egg came first.

There. Copy your way to an A. Or F.

I like the mention of the DNA mutations and speciation, specifically the wolfs to dogs. I love pointing out evidence like that to creationists. There’s fine examples in horticulture too.

The rooster came first, which left the hen somewhat disappointed.