Ontongenetic depth explained — and a challenge for PZ Myers.
The theory of evolution by natural selection does not explain the origin of animal form, because natural selection cannot account for origin de novo of the developmental stages required to construct (i.e., evolve) animals.
In public debates (and personal discussions) with Michael Shermer and Massimo Pigliucci, I’ve met an argument, advanced by both skeptics, which opens interesting and largely unexplored territory in the ID vs. naturalism controversy. In a new article, the science writer and astronomer John Gribbin steps into the same territory, a speculative region familiar to fans of science fiction, not to mention philosophy students with time on their hands and imaginations liberated (perhaps) by alcohol. Back in my early teens, when I lived on a steady diet of science fiction and first saw Stanley Kubrick’s masterpiece 2001: A Space Odyssey, I could have discussed these ideas well into the night. A short blog post will have to suffice today. This figure Read More ›
Okay. First admit the obvious. Ontogenetic Depth (OD) 1.0 was — well, it would be beyond charitable to say utterly inadequate. I realized this not long after reading PZ Myers’ first wave of criticisms. As I’ll explain, however, my realization stemmed not from Myers’ specific points (most of which were either minor quibbles, or missed the mark completely), but rather from trying to apply OD 1.0 myself to the well-studied models systems of developmental biology. The OD 1.0 “metric” was no metric — measuring stick — at all. Thus, PZ’s general judgment in 2004, if not his specific criticisms, was dead accurate: “This is a poorly expressed and unusable idea.”
A few years ago, P.Z. Myers — with his Mencken-like genius for the memorable putdown — devised “Paul Nelson Day,” aka April 7, to record my annual failure to follow up on a promise to elucidate “ontogenetic depth,” a notion I floated in 2003. Much as I enjoy having my own day and all, I figured it was time to explain ontogenetic depth (OD). OD is just not that hard an idea to grasp, in one sense. In fact, OD is downright pedestrian, not much more than a fancy way of saying… Hey, wait a minute. Today is April 6. I still have a few hours to sort it all out. To warm up the audience, here’s an exercise. This Read More ›