Okay, that was lame. No first of either, now that's ridiculous. Check please!
What people don't think about is that every type of animal has breeds, subspecies, or races within that type, just like homosapians. And those breeds did not come from the same "prechicken" source. Before they became similar enough to be categorized as the same animal, the fowl-like creatures were more distinct and clearly not the same animal. Through all of the trials and troubles associated with life and environment, entire pre-chicken creatures die out, leaving similar looking animals that are not related yet are functionally the same.
The reason it works that way is that environmental pressures tend to tailor life toward the most successful for concurrent environment. Very different creatures under the same pressures and mutating forces gradually mutate and evolve toward being almost the same creature, the one most stable form for that environment.
The fact that there are many stable forms for any one given environment and millions of creature types to be pressured into a better fit, yields a variety of stable creature types that are very different from each other and also very different from their origins. An era of entirely new creature groupings gets formed. And many within each group stem from a different origin. The "chicken" got created from a variety of unrelated non-chickens that through their pressured mutating gained the ability to cross breed into an even more uniform grouping. And when the environment shifts very much, it all happens again.
The bottom line is that the thing that you now call "chicken" is the result of a cross breeding of earlier forms of dissimilar chickens that stemmed from cross breeding and mutating of almost-chickens which stemmed from the mutating and cross breeding of a variety of non-chicken creatures.
Within all of that maze of confusion spread over millions of years, the exact moment DNA molecules got altered varies from pre-chicken type to pre-chicken type. Some changes occurred after the prechicken was born. Some occurred during inception. Some occurred within the egg. Some occurred within the sperm. And through the pressures of time, those similar to what we now categorize as "chicken" survived and their pre-chicken ancestors died out after perhaps a very short existence, leaving no trace.
So the real answer is that neither egg nor chicken of what you now call "chicken" gave initial rise to the other. It is like asking which ingredient of the cake came first, the yeast, flour, sugar, egg, .. which? Or perhaps "Who was the first Jew?" The question itself is inadequate.
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony ElseFrom THIS age of sleep, Homo-sapien shall never awake.The Wise gather together to help one another in EVERY aspect of living.You are always more insecure than you think, just not by what you think.The only absolute certainty is formed by the absolute lack of alternatives.
It is not merely "do what works
", but "to accomplish what purpose in what time frame at what cost
As long as the authority is secretive, the population will be subjugated.
Amid the lack of certainty, put faith in the wiser to believe.Devil's Motto:
Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.The Real God
≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is