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To Build a Worm: Where Undirected Evolution Runs into Severe Difficulties


In case anyone missed the punch line of my post yesterday, "Why St. Denis Should Be the Patron Saint of Evolutionary Theory," let me say it again as briefly as possible for the purpose of clarifying matters.

To build a worm like C. elegans from a single cell (the fertilized egg) requires a developmental pathway. In the case of C. elegans, that pathway has been observed in remarkable detail. Every cell in the adult has been traced, via cell division, back to the starting point in the egg. 

Thus, if we want to explain the origin of the adult form of C. elegans, we need first to explain the origin of the developmental pathway that constructs the worm.  And this is where undirected evolution runs into severe difficulties.

The origin of the earliest stages of the pathway (shown in Figure 1 in previous post), where the major cell lineages start (which will eventually divide and give rise to the various structures and tissues of the adult worm), cannot be explained by natural selection — because there is no selective advantage to those stages existing until the adult worm has been constructed. 

But those later stages, especially reproductive capability (a necessary condition of natural selection), cannot themselves exist without the earliest stages laying the foundation. Animal development is the quintessential teleological, or goal-directed, process. It’s an arrow aimed at a distant target. Evolutionary processes, without exception, however, because they are mindless, cannot hit distant targets.  In particular, for natural selection to operate, some selective advantage must be conveyed by mutations or variations in the immediate present.

Neo-Darwinian theory has never explained the origin of animal development for this very reason. Today a range of incompatible evolutionary hypotheses is on offer, but none has solved the puzzle. As I say in the article, it is the biological community’s prior insistence on a materialistic explanation that keeps them stumped and stuck.

The evidence points unmistakably to a cause with foresight; i.e., a cause with a mind. I hope this helps.

Image: C. elegans; see page for author [Public domain], via Wikimedia Commons.

Paul Nelson

Senior Fellow, Center for Science and Culture
Paul A. Nelson is currently a Senior Fellow of the Discovery Institute and Adjunct Professor in the Master of Arts Program in Science & Religion at Biola University. He is a philosopher of biology who has been involved in the intelligent design debate internationally for three decades. His grandfather, Byron C. Nelson (1893-1972), a theologian and author, was an influential mid-20th century dissenter from Darwinian evolution. After Paul received his B.A. in philosophy with a minor in evolutionary biology from the University of Pittsburgh, he entered the University of Chicago, where he received his Ph.D. (1998) in the philosophy of biology and evolutionary theory.