Which Came First - The Chicken Or The Egg?

It's a question that has plagued the minds of humanity from as early as the anceint greeks all the way to the twenty first century, and we're still trying 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?

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 cannot get a chicken egg. But this all depends on the nature and definition of a chicken egg in the first place. Afterall, 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.

During reproduction, two organisms pass on their DNA to the egg. Each time, tiny changes or mutations take place in the DNA. Over thousands of years, these changes create new species. But these genetic mutations must occur in the zygote or initial cell, so a creature very similar to a chicken (which we could call a proto-chicken) would have mated with another proto-chicken and because of a small genetic mutation created the first chicken, which grew in an egg. So the egg came first. This leads to the other side of the story, team egg.

Well team chicken might argue that this was simply a chicken growing inside of a proto-chicken egg. However no-one mutation can ever really constitute a new species. The process of evolution is so gradual that no one proto-chick 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 over many generations we conceived big genetic and behavioral trait differences between them. 

So where does this leave us? We are left with two scenarios. Some early egg laying species gradually lead 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 of what we would classify as a chicken egg and as such the egg came first. Which brings us back to the nomenclature and question of, what is a chicken egg? Which is a fairly meaningless question, but at the end, 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. So, the egg came first.