Which came first - the egg or the chicken? How?
This question points out a really important idea - in sexually reproducing species, life does not "begin", it continues - from generation to generation. You exist because your parents, and their parents, and their parents, passed on some of their genes to you by way of eggs and sperm! As far as chickens are concerned, a really interesting research paper was published in June of 2008. Although it is pretty technical, I think you will be able to understand some of the figures, and the researchers' conclusion - that domesticated chickens are descended from three different species of Jungle Fowl that lived in Asia, including India. (Wild descendents of their wild ancestors still live there today.) BTW - This research points out another important idea - that closely related species sometimes can and do interbreed.
Great question! You're not the first to ask :)
Most experts agree it was the egg. Here's why:
All living organisms evolve over time based on changes in their DNA. A long, long time ago two birds that were not chickens mated. They may have looked something like chickens, but their DNA did not match the DNA of chickens today. When the male's sperm cells and the female's ovum came together, the DNA of the first chicken was realized. This may have come about through genetic mutation or the combination of the DNA.
The zygote that resulted from this occurence contained the DNA of the first chicken. The zygote being inside the egg, the first chicken existed inside the egg.
Of course, the answer begs the question: How did the first birds come about?
Many people believe in different answers, some believe the chicken came first because there had to be another chicken to make a chicken, but others believe the egg came first, probably from a mutated egg that was birthed into a chicken and mutated with another mutated ver and so on. I personally believe in neither of these, i just think it was part of evolution and that an organism that was already out there slowly changed over the years to to natural selection and in the end it became a chicken.
Here is the key to the mystery to this egg VS chicken issue:
The ultimate victor is the chicken, not the egg.
According to the report from the researchers of University of Sheffield and Warwick, a protein called ovocledidin-17 was found to be responsible for producing eggshells, and found only in the chicken's ovaries.
Here's how it works. The OC-17 attaches itself to the calcium carbonate particles to set up a formation, which looks like a crystal structure. It is dropped off once its crystal nucleus is big enough to grow on its own and so this protein replicates more of the similar types of eggshells, causing the amazing egg to be formed.
So, now you know the truth, the chicken came first before the egg.
I just came across this question, albeit a little late, and to my surprise, I don't think it was answered correctly, yet.
Descartes answered this question and he put it simply, and the best, to which almost all philosophers agree:
1) A chicken is actually a chicken.
2) An egg is potentially a chicken.
Actuality must come before potentiality. Something that exists must come before something that will exist later. Therefore, the chicken must come before the egg.
I hope this clears up the confusion.