The white space in evolutionary thinking.
When certain biologists discuss the early stages of life there is a tendency to think too vaguely. They see a biological wonder before them and they tell a story about how it might have come to be. They may even draw a picture to explain what they mean. Indeed, the story seems plausible enough, until you zoom in to look at the details. I don’t mean to demean the intelligence of these biologists. It’s just that it appears they haven’t considered things as completely as they should. Like a cartoon drawing, the basic idea is portrayed, but there is nothing but blank space where the profound detail of biological processes should be.
Let me give an example. This week Discovery Institute released a pair of videos (“How to Build a Worm” and “Switched on Worms”) featuring Fellow and philosopher of biology Paul Nelson and a lowly nematode called C. elegans. Its development is precise and intricately patterned, like a Bach fugue that splits and weaves many voices into one. The final cadence is the newly hatched larva. Not coincidentally, the videos use music by Bach throughout.
C. elegans’s development is a wonder to behold, well worth sharing with the world. But there is more: the development of these lowly worms exposes a major problem with the Darwinian account of evolution.
The development of C. elegans is an end-directed process. As the videos reveal, each embryo follows a precisely choreographed developmental road map in order to get to the final goal — the reproductive adult. None of the intermediate steps on the way to the adult will do. Each step is necessary but not sufficient by itself. Turn aside from this developmental pathway and the result is likely to be a damaged worm or a dead one. Skip some steps and the same is true. How did this process come about? We would say this goal-directedness is evidence for a designer who had the final end in mind, and arranged the proper developmental steps appropriately.
Naw. Like Bach’s music, it all just sorta happened. Guy coulda fallen and hit his head and started writing music like Bach, right? Same with C. elegans.
No surprise, a famous Darwin foulmouth spoke up to that very effect, re the worm:
However, biologist and blogger PZ Myers took exception to this video, claiming that it demonstrates an insufficient understanding of developmental biology. His objection appears to have been its emphasis on teleology — that the worm’s development is directed toward the final adult form — and the conclusion that only intelligent agents can produce such a goal-directed process.
Curiously, Myers’s response avoids engaging Paul Nelson on teleology except to flatly deny it. Myers says that with regard to development, many of the molecular details for C. elegans have been worked out and they are entirely mechanistic and natural, not the work of an intelligent designer. He gives a few examples of how cell fates get specified, and he acknowledges the complexity of the mechanisms involved. He agrees that the more we learn, the more complex things appear. Nonetheless, he says, certain principles can be deduced from what we have learned from other organisms besides C. elegans. Myers summarizes, saying very succinctly: “Development is both hierarchical and incremental.”
But the main problem with Myers’s argument is that there are enormous gaps between his explanation of development and how it might have evolved. You can imagine a simple evolutionary pathway, but when you get down to the nitty-gritty it’s far from simple. I discussed the hypothetical evolutionary sequence in a recent article here, “The White Space in Evolutionary Thinking.”
Myers is a champ at roto-handwaving. His big solution, if we go by his rants in years past is just to fire people who doubt or disagree with him. So one needn’t look for much insight there.
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