Tuesday, May 28, 2013

Poythress on the Adam debate

A few weeks ago I was alerted to Vern Poythress's new article in the latest Westminster Theological Journal, entitled "Adam versus Claims from Genetics." Poythress is a professor at Westminster Seminary and the author of Redeeming Science, where he argues for a form of old earth creationism. He has a Ph.D. in math from Harvard and a Th.D. in New Testament from the University of Stellenbosch.

So I read his article, which you can find at his personal website or reposted at the World magazine website. Honestly, it wasn't something that I wanted to blog about, but then I kept getting more and more emails about it, and it showed up on the World magazine website, so I figured I should say something.

So... The article opens with a brief discussion of the similarity of the human and chimp genomes, and while Poythress says that 99% identity is an oversimplification (which is certainly true), he doesn't just say how similar he thinks the chimp and human genomes actually are. I was relieved that he didn't try to argue too strongly for a vast difference (which is unsupportable), but I sort of wish that he said what he actually thought the similarity was, instead of just leaving his readers to draw their own conclusions. He definitely says that there is similarity - "of that there is no doubt" - so good for him. What do these similarities mean?

The article then turns to the role of interpretation in science, which I found reasonable. He addresses two issues that influence our interpretation of the similarity: purpose and gradualism. On the subject of purpose, Poythress insists that God has a purpose for creation and even if gradualism were true, it still wouldn't rule out a greater purpose of God. On the subject of gradualism, he mostly seems concerned with the occurrence of miracle and whether or not there can be such things. Ruling out the miraculous is a "religious" choice of mainstream science and therefore "Darwinism" has religious characteristics.
But once we question the underlying assumptions, it becomes clear that there are other possible ways of construing the meaning of science: science studies the regularities of God's providential rule, and can do so without making assumptions that ban the idea of divine purposes or ban God's exceptional acts.
So far, I'm fairly OK with what he's written. I would not myself claim that "Darwinism" is a religion, but I can certainly agree that exclusion of the miraculous from science seems like an almost arbitrary philosophical point in some cases. It can be driven by a commitment to philosophical naturalism, the belief that empirical stuff is all there is.

Next he moves on to try to answer the question of how we should interpret the similarity of the chimp and human genomes. He immediately sets a contrast that I hope anyone can see as a false dichotomy:
Now we can return to consider the similarities between human DNA and chimp DNA. What is the meaning of this evidence? It depends on the framework that we have for interpreting the evidence. If our framework is darwinism, with its purposelessness and gradualism, clearly the similarities confirm the standard picture of gradualism. We postulate a gradual series of mutations by which a common pool of ancestors gradually separated into a proto-human and a proto-chimp line. ... If, on the other hand, we use a framework in which God has purposes, he may act either gradually or exceptionally. Whichever means he uses, the DNA is fundamentally his design. The similarities are the product of his intelligent design.
For Poythress, if you already believe in philosophical naturalism (what he calls "darwinism"), then you interpret the similarity as the result of evolutionary relationship, but if you believe in a creator God, then you attribute the similarity to common design. And that's where he started to lose me, because the argument over the historical Adam is not an argument between philosophical naturalists and Christians. It's an "in-house" argument between Christians and other Christians. Turning this into a dichotomy of True Believers vs. Philosophical Naturalists is pretty insulting to those Christians who genuinely believe that the similarity of the human and chimp genomes indicates common ancestry. To be blunt, Poythress seems to want to equate belief in human/ape common ancestry with atheism, but that does not explain why Christians like Dennis Venema or Peter Enns also accept human/ape common ancestry.

Poythress then tries to explain why the human and chimp genomes are so similar by design, which is an admirable goal. I've been trying to get creationists interested in that very subject for a very long time. How does he do? First he appeals to common functions needed for all organisms, which really gets you only so far. As I said in my 2006 chimp genome paper, "The necessity for a common biochemistry for nutrient cycles does not explain why chimpanzees exist." To his credit, Poythress acknowledges this very point:
Does it make sense that God would create human beings with so much similarity to animals? Again, it is up to God how he wants to do it. If he wants to make similarities, he can do so - however many similarities he wants.
You can see that Poythress doesn't answer the question right away. Yes, it's true that God could have created us very similar to animals, but it's also possible that God could have created us very different from animals. The question is why?

Again to Poythress's credit, he does try to answer to this harder question:
But it is interesting that the Bible does give hints concerning similarities between human beings and the animal world. Genesis 2:7 says that, when God made man, "the man became a living creature." The expression "living creature" is the same as the expression used in Gen 1:20, 21, and 24 to describe animals. man is created from "dust from the ground" (2:7), which also hints at the common material stuff making up his body. Man made in the image of God is supreme over the animals (1:28), but he also has a definite solidarity with them.
OK, now I think he's onto something. The article develops this theme of solidarity with creation by drawing a parallel with the Virgin Birth. Jesus presumably had a Y chromosome, yet he did not inherit that chromosome from any earthly father. Jesus' Y chromosome demonstrated His solidarity with humanity, and so too, our similarity to animals demonstrates our solidarity with creation as its intended rulers. I really liked that idea, and I liked the way Poythress's article developed it. It doesn't satisfactorily explain the degree of similarity between the chimp and human genomes, but it's a really good addition to our creationist understanding of biological similarity.

Then the article turns to "junk DNA" and whether or not its functional, a topic which does not interest me much. So let's skip ahead to his coverage of ancestral population size, wherein he mostly just says there's room to doubt reconstructions of ancestral populations. I was dissatisfied with this approach, but it's not surprising. The population reconstructions are complex and not easily understood by laypeople right now. So creationist responses lag behind the current science, and the best your typical creationist can do is cast aspersion on the science. Until we have a creationist well-trained in modern theoretical population genetics, I think we will continue to have only unsatisfactory answers to these ancestral population reconstructions.

The article concludes by reiterating its main points and assuring the reader that
...we may continue to have confidence that he gave us a reliable account when he spoke about Adam and Eve. They did exist, and they were specially created - "in the image of God." Because of Adam's fall, we are all subject to sin (1 Cor 15:21-22; Rom 5:12-21). We must come to Christ for deliverance.
So there you go. For me, the article was a mixed bag. The false dichotomy of "darwinian"-vs.-Christian really bothered me, and there was too much appeal to ad hoc, "God-could-have-done-it-that-way" arguments. But I also really, really liked the idea of solidarity, even though it doesn't fully explain the similarity of the human and chimp genomes. The notion that we have a connection to this world by virtue of our creation as rulers ("image of God") is great. That's definitely an idea worth developing.

Feedback? Email me at toddcharleswood [at] gmail [dot] com.