I came across a fascinating post at an Intelligent Design Creationism blog, called “micro vs. macro evolution – where to draw the line?”
Given the source, and the title, I immediately chuckled. Of course, this is a very difficult question for those whose religious beliefs lead them to reject the overwhelming evidence in support universal common descent. I’m going to offer some excerpts from this post in order to point out a few common themes among conservative Christians and their relationship with Intelligent Design proponents (most of the latter fall into the former category, but many Young Earth Creationist Christians have problems with the ID guys). First sentence:
Like many Christians (and unlike many Intelligent Design purists), I believe that Darwinian evolution cannot possibly account for the diversity of KINDS of animals.
Notice immediately the language of “belief.” There is no appeal here to evidence for a point of view, as this poster isn’t even trying to pose as interested in the science of it all. Also, the concept of “kinds” is highly ambiguous. What makes mammals a different kind from birds? Where’s the line between birds and reptiles (of which they are actually a subset)? Where do you stick a platypus, or an archaeopteryx?
I believe that our designer designed each KIND independently. But, as I mentioned in a previous blog post, it’s clear the designer recycled designs in a pattern roughly parallel to the evolutionists’ discredited “tree of life.” And at this point I have to make an unpleasant conceit to godless evolutionists: the designs of many parts of our body appear to be modified versions of those used in the design of apes. Yes, these smelly, dirty, brutish animals served as a launching point for our design and, though we certainly didn’t descend from them, we have a certain designerly connection to them, much as Windows Vista does to Windows Millennium Edition.
The adjectives are quite fun. Godless evolutionists may certainly describe Dawkins and PZ Myers, but it would be a hard term to fit to Francis Collins. There are probably more religious people who think the theory of evolution is well-proven then there are non-religious people, simply because there are more of the religious, at least in this country.
And of course, animals are “smelly, dirty, brutish” but we could never, ever have descended from them. What evidence is offered as refutation? None. And of course, there is no indication that the writer has considered the overwhelming evidence for universal common descent, be it fossil or genetic. It’s all about what one chooses to believe. In this sense, many believers are much more postmodern than the evolutionists who they think lack a belief in truth. Fascinating.
Then, the poster goes on to say that there is diversity within a population, and that certain traits will be selected for, thereby ceding that evolution occurs on certain scales. So why can’t it account for new “kinds” (whatever those are)?
But it is micro-evolution, and never strays outside the boundary of a KIND. A dog cannot evolve into a cat. In ten million years, I contend, a dog’s descendants will still be recognizable dogs. Indeed, even after a billion years of microevolution, a dog’s descendants will still be something other than cats.
This is silly. If change occurs, then over more time, you have more change. Now of course evolutionary biologists would never claim that a dog would turn into a cat. What they do note is that if at some point in those ten million years you have two populations of dogs that are separated for a period of time, by geography or habits or any other factor that prevents interbreeding, those populations will diverge over time. That’s speciation. And that is considered by many to be the dividing point between micro- and macroevolution. Natural selection does not pretend to predict a dog will become a cat, but to explain that dogs and cats at some point diverged from some common ancestor that had biological similarities to both. The prediction made is that any two other groups separated for a period of time will eventually diverge as well.
But where do we draw the line between kinds, between microevolution and macroevolution? Can a donkey be bred from a horse? Can an alpaca be bred from a camel? Can a tiger be bred from a lion? These all may sound in some way ridiculous, but all of these animal pairs can interbreed, which suggests that they may be of the same kind. Where things can get tricky is when the hybrid born of the mating is itself sterile. Does this mean we’ve crossed a line between kinds, and found the limits of what evolution can change?
These cases of species that are close enough to interbreed but not produce fertile offspring are excellent examples of the fluid nature of biological change. Tigers and lions can produce offspring because they diverged recently enough that they have yet to accumulate the level of genetic difference necessary to prevent all reproduction. However, they have diverged enough to be both noticeably different (unlike species that we humans can’t tell apart with our naked eyes) and noticeably incapable of producing fertile offspring (unlike some species of songbird that while they do not reproduce together in the wild for behavioral reasons, are still physically capable of doing so). Again, an excellent example of speciation and evolution at work, breaking down the idea that each “kind” was created in a perfect, separate form.
I myself have no particular problem with a theory suggesting that all cats are descendant from a common ancestor. I’d even concede that all birds share a common ancestor – from hummingbirds to ostriches. Given enough time, I could see that change happening – it’s just a few orders of magnitude beyond the flexibility humans have brought to the domestic dog. Some quasi-evolutionists even allow for all of Primates (soulless monkeys and apes lumped together with humans) to have descended from a single designed ancestor. I myself could never believe such a thing, since I find it revolting to think my ancestors might have been animals.
Instead of the argument from personal incredulity, you get the argument from personal revulsion. Methinks this blogger has too high a view of humans and too low a view of animals. Biologically speaking, that is.
Some Intelligent Design proponents such as Michael Behe go so far as to say that yes, all species evolved from a common ancestor. They’ve been exposed to the evidence enough to know that arguing against this well-proven fact is simply impossible. However, to maintain some “proof” of an involved God from the physical world (pure faith is the enemy) they take their criticism to the level of evolutionary mechanisms. This critique still fails, but is substantially more subtle than run-of-the-mill Creationism, and has enough pseudoscientific sounding jargon backing it up to fool the scientifically uneducated market they’re aiming at: America’s conservative Christians.
And then you get tension between Christians who believe what they believe because it feels right (and/or it jives with their relatively unscrupulous reading of Scripture) and those Christians who are trying to make a (in their view) scientific argument for believing something. But this blogger talks about the revulsion that rely underlies all of Creationism, including the Intelligent Design movement: many simply reject the proposition that God is not necessary to account for the origin of the human species because it is religiously unpalatable. These rejectionists laud people like Behe (look, he says random mutation doesn’t work!) or Collins (look, a scientist who still believes in God) or Einstein (look, a guy who misleadingly uses the word “God” when talking about nature, thereby confirming our hopes that he’s on our side) to support what they believe by faith, and reject the parts they dislike.