June 03, 2006

Egg vs Chicken

A geneticist, a philosopher and a chicken farmer teamed up to answer the old riddle/koan (wiki def) of "Which came first - the chicken or the egg?"

The verdict via BBC and my retorts:

Charles Bournes, chairman of trade body Great British Chicken, said:
"Eggs were around long before the first chicken arrived. Of course they may not have been chicken eggs as we see them today but they were eggs."
  • Bournes is a smartass. He doesn't answer the implicit question. Yeah, duh. Dinosaurs have eggs and dinos came before chickens. The question is more challenging when it is about chickens and chicken eggs.

Professor David Papineau, an expert in the philosophy of science at King's College said:

"I would argue it is a chicken egg if it has a chicken in it. If a kangaroo laid an egg from which an ostrich hatched, that would surely be an ostrich egg, not a kangaroo egg,"
  • Papineau invokes a bizarre thought experiment to justify his claims. A crossbreed of two separate species of birds emerges from the first chicken egg as a chicken, unrelated to either parent because of magical X-Men styled mutations. He'll get credit for his "critical thinking" in eliminating the circuitous definition loop of "the first chicken must come from the first egg but ooh, that egg must have come from the first chicken so that was it, but the egg again..." but ostriches and kangaroos? What is this guy talking about?!? Papineau doesn't understand evolution at all. Lets see what the evolutionary biologist had to say.
Professor John Brooksfield of Nottingham University said:
"The first living thing which we could say unequivocally was a member of the species would be this first egg, so I would conclude that the egg came first."

    • Bravo! That was concise. An egg has the same DNA as its resultant chick, so the egg is the first "instance" of chicken. Perhaps he could have defined the term "species" somewhere and he would have been on solid ground. I'll get to that in sec.

    These arguments are disappointingly bland from this assembly of "eggsperts" (which incidentally, were assembled by Disney to promote the DVD of their movie Chicken Little.) Where are the deep philosophical ponderings of potentiality and realization? What about the speciated definitions artificially separating chicken (Gallus gallus domesticus) from its pheasant ancestor "Red Junglefowl" (Gallus gallus)?

    What makes an egg? What makes a chicken?

    Here's what I think.

    An egg refers to the reproductive component of a mother (possessing half the genetic material needed to create a genetically unique individual.) The "egg" in question is different -- it is the external, calcified shell as well as the fertilized egg of a hen.

    A chicken is an assembly of phenotypic characters (things that we can readily observe and quantify) of a particular animal. On a child's level -- does it crow and cluck? Is it short with a small beak and fluffy feathers? Does it think that the sky is falling? Zoologists go into great detail thinking up as many characters as they can, but even then "species" can be a hotly debated term. If they can crossbreed, they are generally considered to be the same species. Unless they are geographically isolated or they have different mating behaviors. But only with certain animals.

    If we go this far, the answer is that the chicken came first and Prof Brooksfield gets the points for the most valid argument.

    However, the question is flawed. The experts get a solid F for failing to recognize this. It is not an either/or question, it happens (relatively) simultaneously. You cannot define a species based on one individual. It might represent the earliest known example, but it is just that -- an example. Species are population-based. Meaning that in order for us to know what makes a chicken egg and a chicken, we need to see a family of them.

    I don't know much about dogs. I might see one walking its owner down the street and think "oh look there's a dog." Someone else might say "ooo, what a cute doberman/chihuahua/poodle!!" A tall dog back in the day was mated with other tall dogs and eventually the great dane became a type of dog. That is what drives speciation -- random or sexual selection of characters. This takes a looong time. Our pet dogs haven't even speciated yet.

    The idea of "First Chicken" is ridiculous. This in turn, makes the idea of "First Chicken Egg" equally silly. In order to recognize them as something special, they need to be a part of a group.

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