Over the last few days, I've been reading the articles in the latest issue of Evolution: Education and Outreach. This is a fairly new journal with the mission stated in the title, and I have to say that it is very, very good — the articles are almost always easily readable, and they address significant issues in the public understanding of evolution. This particular issue focuses on transitions, and not just on transitional fossils, but all kinds of evidence for change over evolutionary time. It's been commented on by Larry Moran and Jerry Coyne, and they're entirely right that these are extremely useful articles, not just in providing helpful data when addressing arguments about evolution, but they're also loaded with figures that I'll be stealing using for my own lectures.
I have to say something a little peculiar, though. It's not really a criticism, because I'm not going to argue against these articles at all—I repeat, they are informative and useful and great to read! However, I am concerned that they address one audience, but it's not the audience we have to really worry about. The kinds of people who will read and enjoy those articles are scientists who appreciate a good overview of a field, the kinds of informed citizens who would, for instance, read a science blog, and educators in general who want more substance about evolution to include in their classes. Creationists are not the journal's clientele. That means that sometimes the articles miss the mark on who we need to persuade.
For example, T. Ryan Gregory's overview of the principles of natural selection, Understanding Natural Selection: Essential Concepts and Common Misconceptions, makes an important point: selection is surprisingly difficult for many people to grasp. This is entirely true, but we sometimes mislead ourselves because once you get those few basic principles, and I mean really understand them, suddenly selection seems simple and even intuitive…and most of us doing the teaching and public outreach are solidly in that blissful state of easy comprehension.
And this isn't at all unusual. Gregory provides a taxonomy of common conceptual errors, and points out that many of these errors, such as the idea of inheritance of acquired characters, have been held by some of the greatest minds of Western civilization, from Aristotle to Darwin.
Here's the catch: we can see how to explain selection to Aristotle and Darwin now, but unfortunately, creationists are not a collection of Aristotles and Darwins. I wouldn't go far the other way and say they're all stupid, but they do have lots of ideas that are so egregiously wrong that they don't fit into Gregory's schemata.
For instance, here's a nice diagram of correct and incorrect views of how selection works.
A highly simplified depiction of natural selection (Correct) and a generalized illustration of various common misconceptions about the mechanism (Incorrect). Properly understood, natural selection occurs as follows: (A) A population of organisms exhibits variation in a particular trait that is relevant to survival in a given environment. In this diagram, darker coloration happens to be beneficial, but in another environment, the opposite could be true. As a result of their traits, not all individuals in Generation 1 survive equally well, meaning that only a non-random subsample ultimately will succeed in reproducing and passing on their traits (B). Note that no individual organisms in Generation 1 change, rather the proportion of individuals with different traits changes in the population. The individuals who survive from Generation 1 reproduce to produce Generation 2. (C) Because the trait in question is heritable, this second generation will (mostly) resemble the parent generation. However, mutations have also occurred, which are undirected (i.e., they occur at random in terms of the consequences of changing traits), leading to both lighter and darker offspring in Generation 2 as compared to their parents in Generation 1. In this environment, lighter mutants are less successful and darker mutants are more successful than the parental average. Once again, there is non-random survival among individuals in the population, with darker traits becoming disproportionately common due to the death of lighter individuals (D). This subset of Generation 2 proceeds to reproduce. Again, the traits of the survivors are passed on, but there is also undirected mutation leading to both deleterious and beneficial differences among the offspring (E). (F) This process of undirected mutation and natural selection (non-random differences in survival and reproductive success) occurs over many generations, each time leading to a concentration of the most beneficial traits in the next generation. By Generation N, the population is composed almost entirely of very dark individuals. The population can now be said to have become adapted to the environment in which darker traits are the most successful. This contrasts with the intuitive notion of adaptation held by most students and non-biologists. In the most common version, populations are seen as uniform, with variation being at most an anomalous deviation from the norm (X). It is assumed that all members within a single generation change in response to pressures imposed by the environment (Y). When these individuals reproduce, they are thought to pass on their acquired traits. Moreover, any changes that do occur due to mutation are imagined to be exclusively in the direction of improvement (Z). Studies have revealed that it can be very difficult for non-experts to abandon this intuitive interpretation in favor of a scientifically valid understanding of the mechanism.
This is very nice. I can see using this in my freshman biology class right away — it's very handy to be able to contrast correct and incorrect views, and it would provoke some thinking and discussion, since I know many of my students think just like the right panel illustrates (at least, before I'm done with them they do). Of course, my students tend to be motivated to understand, with some background in biology already, or they wouldn't be biology majors.
Unfortunately, whenever I sit down and talk with full-blooded creationists, their views aren't even incorrect. They're so wrong, they're completely off of Gregory's charts.
For a public example of this phenomenon, look at Ray Comfort's ideas about the evolution of sex. He seriously believes that every kind of animal had to independently evolve all of its primary properties in one sudden sweep. When elephants evolved, they had to simultaneously evolve female elephants; the idea that some traits do not have to evolve anew because they are shared with the parent population is incomprehensible to him.
Another fellow with a similar misconception is Jim Pinkoski, who states this idea rather baldly.
If "evolution" is true, then each major life form would have to evolve it's own eyes (as well as every other major organ of its body)!
He illustrates this with a picture of a T. rex that has evolved a single eye, and then "wants" to evolve another eye. This is a really common belief, that new features arise as a consequence of desire by individuals.
These are the beliefs of the people doing public outreach on behalf of creationism, and the ordinary guy who passively accepts this stuff is even weirder. Every time I've had a one-on-one conversation with a casual creationist, there is always a moment when I am weirded out to the max by some genuinely twisted irrationality they trot out in their defense. We make a mistake when we look to the intellectual history of an idea to figure out how they rationalize creationism, because there is virtually no intellectual history there. They are not building on a foundation of ideas at all — they have a religious preconception of how species arise, and their vision of evolution is a hodge-podge of ad hoc contrivances chosen specifically to be absurd and unbelievable. They are not trying to explain, as Aristotle and Darwin were; they are trying to invent reasons to reject.
Like I said, this is not a criticism of Gregory's paper, which does an excellent job at its purpose of making reasonably knowledgeable people even better informed. I think, though, that there's a missing piece in the story: how do we turn grossly ignorant people into reasonably knowledgeable people? That's a really difficult problem.
This is an even bigger problem in the other articles in the issue. For instance, probably my favorite article in the whole issue was Edgecombe's Palaeontological and Molecular Evidence Linking Arthropods, Onychophorans, and other Ecdysozoa, which weighs the evidence in the great dispute between the cladists who favor a grouping of invertebrates into an Articulata clade, vs. an Ecdysozoan clade. It's grand, big-picture macroevolution, discussing the relationships of whole phyla in deep time, and it also promotes the importance of multi-disciplinary thinking, basing conclusions on molecules, morphology, and fossils. It isn't shy at all about bringing up the problematic taxa (where the heck do tardigrades belong, anyway?) either. It's a wonderfully chewy article that helped clarify my perspectives on the discussion.
Again, not a complaint — this article is going straight into my file of very helpful reviews. But now imagine sitting down over coffee with an enthusiastic Hovind supporter right after church; this article is going to lose him right at the title. He doesn't know what you mean by arthropod, let alone onychophoran. Throw articulata, cycloneuralia, and ecdysozoa at him from the abstract, and he's going to tell you how much smarter the Hovinds are than you, because at least what they say is in English and makes sense to him.
This is tough stuff. How I would explain this paper to you, the readers of a blog like Pharyngula, would be close to what Edgecombe wrote, but how I would explain it to a run-of-the-mill church-going creationist would have to be very different. I think the way I would try it would be to start with figure 1 from the paper, which shows diverse representatives of the Ecdysozoa:
Examples of the phyla of molting animals grouped with arthropods in Ecdysozoa. a Nematoda (Draconema sp.); b Nematomorpha (Spinochordodes tellinii); c Loricifera (Nanaloricus mysticus); d Onychophora (Peripatoides aurorbis); e Tardigrada (Tanarctus bubulubus); f Priapulida (Priapulus caudatus); g Kinorhyncha (Campyloderes macquariae).
Then I would explain that the paper describes the multiple lines of evidence that support macroevolutionary explanations for how all these extremely different kinds of invertebrates had a common ancestor, and then let him raise any questions about how it was done. And I would brace myself for some radically weird questions that I would never have imagined ahead of time. This is a business where flexibility is a requirement.
I am not saying that my hypothetical creationist conversationalist is stupid at all — but that he is grossly uninformed and misinformed, and comes from a background that did not provide him with the rational history of the ideas that would give him any reasonable context with which to even consider the paper. It's a missing piece of the mission for evolutionary outreach: how do we wake those people up?
Don't let that dissuade you from reading the journal, though. I think that where it helps most is that it will give non-experts with a reasonable grounding in science more information that they can use in arguments with creationists. When it comes to communicating the information to others though, you're on your own…and in a lot of ways, that part, getting complex ideas across to people who are actively denying the evidence, is the hardest part of the story.
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