Which came first-chicken or the egg?

Haha, guys. Now here's an interesting question. Which comes first-chicken or the egg. I am sure you all are very familiar with this question and it has bothered scientists for years. If the chicken came first, then didn't it hatch from an egg? And if the egg came first, wasn't it laid by a chicken? It's one of those questions that seem unanswerable. Till today, the question remains unsolved. I came across this question a long long time ago, and was very inquistive to check it out. I did abit research on the internet and i hope you guys could give me more information to really have a better grasp and understanding of the topic.
Chickens hatch from eggs, but eggs are laid by chickens, making it difficult to say which originally gave rise to the other. If the egg is not necessarily of any specific type: Then it could be said that the egg came first, because other animals had been laying eggs long before chickens existed. Egg is defined as a normal egg in this way. If only an egg that will hatch into a chicken can be considered a chicken egg, then maybe a chicken laid the first chicken egg which contained the first chicken. In this case the chicken egg came before the chicken. If only an egg laid by a chicken can be considered a chicken egg: Then, The first chicken (which hatched from a non-chicken egg) laid the first chicken egg. In this case the chicken came before the chicken egg.
However, there is a scientific way of looking into the problem. living things evolve through changes in their DNA. In an animal like a chicken, DNA from a male sperm cell and a female ovum fuse to form a zygote -- the first cell of a new baby chicken.Then, it divides many times to form all of the cells of the complete animal. In any animal, every cell contains exactly the same DNA, and that DNA comes from the zygote.
Chickens evolved from other animals(i think is some sort of winged beasts)through small changes caused by the fusion of male and female DNA or by mutations to the DNA that produced the zygote. These changes and mutations only have an effect at the point where a new zygote is created. That is, two winged beasts(probably) mated and the DNA in their new zygote contained the mutation(s) that produced the first true chicken. That one zygote cell divided to produce the first true chicken.
Prior to that first true chicken zygote, there were only non-chickens. The zygote cell is the only place where DNA mutations could produce a new animal, and the zygote cell is housed in the chicken's egg. So, the egg must have come first.
But there are other definitions. I could be a bit unrealistic as i personally felt that the question is phrased the wrong way. If this is the question, i would like to ask everyone -how life existed and how the universe was formed? Even though we all say man are probably descended from monkeys but that is only an assumption. So, if chickens are descended from non-chickens, then when did the evolution began? How do we know what is the first human? Hence, i felt that there is no correct answer.
Guy, i hope ou all could help me improve by giving your opinions on the mind boggling question. Thank you.