So this question was asked in one of my college classes: which came first, the chicken or the egg? Interestingly enough, of all the science courses I take/have to take, this question was asked in a non-biological or non-evolution course (Energy and Climate). I should be working on my 15-20 page paper but I shall do this instead lmao.
So I’m going to try to answer this question with my knowledge of science. I am not claiming what I think is right or even supported with evidence.
All life evolved from single-celled organisms. Some of them evolved to be multicellular, some remained unicellular. Some went with sexual reproduction to have young, others stayed with cloning techniques like binary fission. The chicken is a multicellular organism that reproduces sexually and lays eggs.
The question is: which evolved first? The distinguished body structure of the chicken or the adaptation to lay eggs for reproduction? I might be able to find an answer if I did some research into scientific journals but to the best of my knowledge, I think all birds lay eggs, which would mean that this trait is older and more ancestral. It must have been passed down to all families of birds that descended from the bird line.
So if we consider a ‘chicken’ the thing we think of today in farms, then the egg probably came first because the egg-laying characteristic was developed first in history, before the standardization of the modern chicken. There had to have been an egg first from which the first modern-structure chicken hatched.
However if the question ‘chicken or egg’ is talking about birds in general rather than only chickens, then the bird must’ve came first. This is because the egg-laying property is something that an organism adapted to do in the past, but there must have been a first organism that laid eggs in the first place that can be defined as a bird. Laying eggs is one of the unique properties of a bird so the first bird that laid an egg is considered a bird. The parent of this bird was an organism that did not lay an egg to have that first bird because then the parent would’ve been the first bird.
In this case, the chicken came before the egg because we are talking about the first organism to lay an egg (for birds).
Science makes things complicated. But science makes things more efficient. I know I made this question seem complex, but there are too many variables. I didn’t discuss things like, what points define a chicken? Are we talking about the modern chicken or any of the chicken ancestor species? Are we talking about the egg cells within all females (in this case hens) or the egg structure that comes out with the shell and stuff?
My professor responded to that question by saying there has to be a yes or no, one or the other. The chicken or the egg. To him, this was black or white but he just didn’t know the answer. This professor is not a biologist. He doesn’t have the background in evolution like I do. He doesn’t know that this question is too broad to be answered easily.
But if someone were to ask me which came first, I’d just say the chicken because organism morphology came before reproductive qualities.
Or just so I don’t have to get into details like I am doing now.