Monday, May 26, 2008

The Chicken and the Egg - An Inductive Analysis

In a slight departure from my usual computer science focused musings, I'm going to analyze another logical conundrum that has raged for centuries. Which came first, the chicken or the egg?

One of my many online debates clued me into the fact that there is a widespread belief that the egg came first. I even found a "paper" providing an in-depth analysis concluding the same. Unfortunately, the analysis appears flawed. An e-mail to the author bounced, so I figured I might as well post my brief analysis here.

A simple inductive analysis suffices to conclusively determine the causal chain.

Base case: single celled organism, asexual reproduction via mitosis (given our current knowledge)
n implies n+1: species n produces, by its own reproduction mechanism Rn, an offspring n+1 with a slightly different reproduction mechanism, Rn+1.
Conclusion: the "chicken" came first.

In this case, our "chickens" were not hatched from "chicken eggs", but were instead hatched from the "chicken's" progenitor's egg type. The authors of the paper attempted to disregard this semantic interpretation under "Chicken Precision", but as this is a metaphor, a "chicken" is merely a stand-in for a particular species to be substituted at will.

Thus, the only universally quantifiable proposition is that the "chicken" came first, since the first egg-bearing species, Sn+1 and Rn+1, was produced from some non-egg-based reproduction mechanism, Rn. The contrary proposition that the egg came first contradicts the base case of the above inductive argument where we know reproduction was based on asexual mitosis.

Unless our understanding of early biology changes radically, metaphorically and literally speaking, "chickens" came first.

[Edit: I posted an update to elaborate on why I believe my interpretation is more faithful to the original intent of the question, as first formulated in ancient Greece.]