OK, how about some chicken embryology. I’m not an expert by a long shot, and maybe someone else can fix my mistakes… but I think the yolk and the white are part of, or develop from, the oocyte. The oocyte is a big cell, containing a nucleus with half the genetic material of the future chicken. Traveling down the oviduct, the oocyte may get fertilized and an embryo will develop. The shell gets deposited later.
Going backwards even further, the oocyte comes from a germ-line cell that buds off the pre-chicken mother when she is still an embryo. And the yolk comes from nurse cells (at least in fruit flies, and I’m only guessing this is true in chickens) that differentiate from the germ-line cells.
So, in a sense the inside of the egg exists before the new chicken (i.e. fertilized oocyte —> embryo), except that it forms from the germ-line cells, which are different from ordinary mother cells. So, are these germ-cells conceptually pre-chicken mother cells or future-chicken cells?
And when does a new species begin, genetically speaking? When does the critical mutation occur that would create a new species? During meiosis? During fertilization?
If the critical mutation leading to a new species occurs in the male pre-chicken, then… um…
Never mind, I am just confusing things. Either someone needs to rescue me or everybody just ignore this post altogether!
But as I said, it won’t work, or at best would be completely meaningless and misleading. Lines between extant species are more or less a marker of where there have been separate branches of ancestry.
Placing a divider between an organism and its parents is not the same, because evolution doesn’t happen to individuals, it happens to populations, and the genetic variation between individuals in a population is likely to be greater than the genetic variation between a single organism and its parents.
I am not sure about the chicken are eggs laid by chickens thing. I think that chicken eggs are eggs that produce chickens. What if some day we use chicken eggs as a host for other species, maybe even cloned dinosaurs. If I looked at a group of them, I would say that they are dinosaur eggs rather than chicken eggs.
Perhaps you mean that they have the *potential * to produce chickens? Most of the eggs commonly referred to as chicken eggs today produce no chickens at all.
Well, visible light is a continuous spectrum but we seem to have no problem at all saying “The colors are red, orange, yellow, green, blue, indigo, violet.”
So, if you’re a fundamentalist, the question has an answer. If you’re not, then it’s unanswerable or at best really complicated. Sounds like a perfect metaphor.
This is the Straight Dope Message Boards, right? It’s connected to the Straight Dope homepage and Archives, wherein is contained Cecil’s wisdom, right? Searching on “chicken” and “egg” gets me: Which came first, the chicken or the egg?
There is no logical reason that the “someone to care for the young” has to also be a chicken. I vote for egg. The first chicken came from its egg. It was a mutant offspring of chicken-like parents.
Actually, that is not the case. You will never find an individual of a species that has mated with another individual of that species giving birth to a different species.
Actually, that is not the case. You will never find an individual of a species that has mated with another individual of that species giving birth to a different species. Individuals don’t “cross the line,” populations do.
