We’re considering a popular article in which David Gelernter (who’s not a biologist) attacks evolution. This critique beings with part 1.
Evidence for evolution
Gelernter makes the “okay, microevolution happens, but not macroevolution” argument in a clumsy way. Macroevolution is usually defined by biology textbooks to mean speciation—that is, not just change within a species but enough change to make a new species (or more).
That doesn’t sound like what he’s talking about here.
But mutations to these early-acting “strategic” genes, which create the big body-plan changes required by macro-evolution, seem to be invariably fatal. They kill off the organism long before it can reproduce. . . .
Evidently there are a total of no examples in the literature of mutations that affect early development and the body plan as a whole and are not fatal.
What he’s apparently talking about is phylum-level changes, which is at a much higher level than speciation.
In the first place, I get my biology from biologists, so have them tell me that phylum-level changes are impossible.
Second, apparently you’re startled that there are no examples in the literature of phylum-level changes. Do you think new phyla have appeared in your lifetime? Do you expect someone to have documented the change? Or are you saying that we should have examples of the complete sequence of mutations, horizontal gene transfers, or whatever that created one or more new phyla? Whatever deal breaker you imagine for evolution is not clear. It sounds like your complaint is that we haven’t seen a thing we have no reason to expect to have seen—is that surprising?
He then quotes a researcher: “We think we’ve hit all the genes required to specify the body plan of [the fruit fly]. . . . [None is] promising as raw materials for macroevolution.” But this is from a presentation in 1982, which is 37 years ago! Biology is a fast-moving field. If you’re going to ignore the scientific consensus and avoid any sources but those that support your minority opinion, at least use recent findings.
He quotes another biologist who referred to a “great Darwinian paradox.” This paper is from 1983, so again we need to see what today’s biologists would make of the issue. And the paper isn’t even dismissive of evolution. (For those who want more, I’ll let you follow up with the rather involved biological argument in the source.)
Is Intelligent Design a viable alternative to evolution?
Gelernter says that Intelligent Design (ID) is the obvious response to the Cambrian explosion.
The theory suggests that an intelligent cause intervened to create this extraordinary outburst. By “intelligent” Meyer understands “conscious”; the theory suggests nothing more about the designer.
The subtext in that last phrase is that there is nothing in ID to suggest religion. But it’s hard to imagine what suggesting an intelligent Creator is if not religion. Sure, you can imagine super-smart aliens (rather than deities) behind life on earth, but the Christian will immediately wonder what created them, not satisfied until we’ve reached the Christian god.
Gelernter imagines skeptics wondering where the evidence for ID is:
To Meyer and other proponents, that is like asking—after you have come across a tree that is split vertically down the center and half burnt up—“but where is the evidence of a lightning strike?” The exceptional intricacy of living things, and their elaborate mechanisms for fitting precisely into their natural surroundings, seemed to cry out for an intelligent designer.
And we’re back to the childish “Golly, it sure looks designed!” Uh, yeah, and the earth sure looks flat.
My favorite example of the principles of evolution tested and proven to succeed is the discovery of Tiktaalik, a plausible transition between fish and land animals. Knowing the date that such an animal would’ve lived, paleontologists found exposed sedimentary rock of the right age. They searched, and there it was.
My favorite rebuttal to all ID arguments is: evolution is the consensus of the scientists who understand the evidence. Laymen (that is, scientific outsiders) are stuck with the scientific consensus as the best explanation. Of course, that consensus could be wrong, but it’s our best bet.
And my favorite summary of the power of evolution to explain life is from Richard Dawkins:
The ratio of the huge amount that [evolution] explains (everything about life: its complexity, diversity and illusion of crafted design) divided by the little that it needs to postulate (non-random survival of randomly varying genes through geological time) is gigantic. Never in the field of human comprehension were so many facts explained by assuming so few.
The arguments from ID proponents aren’t arguments for their own theory (as they would be if coming from scientists actually trying to follow the evidence). All they can do is try to crap on evolution. I find none of these arguments convincing, and wouldn’t follow them if I did. I get my biology from biologists.
Worse, “Intelligent Designer did it!” raises far more puzzling questions than it answers. Who is this Designer (or Designers)? A god we know about or a new one or something else? You can’t just say that a Designer did it and then think you’ve resolved anything. You’ve now got a new, bigger problem: justifying your remarkable claim. Get to work.
The silver bullet argument that takes down Intelligent Design is the fact that there is zero evidence for such a designer. The religious or spiritual people of the world have come up with countless supernatural beings, but none of them are universally agreed to. The contradicting supernatural claims among religious people themselves show that religious claims can’t be justified.
Continued in part 4.
is nothing more than a battle of wits
between two unarmed sides.
— Hemant Mehta (The Friendly Atheist)
Image from kazuend, CC license