Thursday, February 9, 2012

Iron Man, Marching Bands, and Embryos

The other night I paused as I was flipping through the channels to watch a part of the Iron Man movie where Robert Downey, Jr. is encased in his hi-tech iron man suit. As all of the robotic assemblers timed and coordinated their operations with magnificent precision to construct the suit around Downey's body I was reminded of an article I'd read that afternoon which describes how a developing human embryo is assembled in pretty much the same way.

The coordination, timing and precision needed to assemble the iron man suit, as exacting as it is, is really a pretty simple affair compared to that which takes place in every developing child. After all, the iron man assembly process was presumably intelligently designed by human engineers, but embryonic assembly is designed to unfold by .... what? Accident?

Here's the article's lede:
Embryonic development unfolds as if it were a symphony and the members of the orchestra were the various genes that are turned on and off in the course of development. Every player must perform his part at the right moment and in the right way, otherwise the delicate balance of turning on and off signals will be disrupted, with catastrophic results. Scientists have been uncovering layer upon layer of complexity that seems to point to a symphony of processes that could only have been orchestrated by design.
In the embryo, cell processes, like musicians in an orchestra, are turning on and off with astonishing precision, but even more astonishing, perhaps, is that while they're doing this they're also migrating to precise locations around the embryo. Embryonic cell activity is actually more like a highly accomplished marching band performing a halftime show than it is like a stationary orchestra.

Imagine a band instructor leaving to chance whether the band members will play their instruments properly while moving to their assigned spots on the field at just the right time. How long would it take for a band of several hundred members to hit upon just the right pattern if every time the wrong pattern was formed the band is disqualified and another band takes its place? After all, if an evolving embryonic process gets it wrong the embryo dies.

It takes enormous faith, blind faith, in chance and serendipity to think that such a process evolved naturalistically, but blind faith is not in short supply among naturalists.