I really enjoy reading pieces written by smart, intelligent, thoughtful individuals, even if I do not agree with their conclusions. They make valid points and provide some useful perspectives on complicated issues. One case in point is this review of Larry Moran’s book “What’s in your genome?” by Gert Korthof.
What I would like to highlight today, is that his review brings up a valuable lesson: the importance of charity when advancing viewpoints that critique prevailing modes of thought.
I strongly encourage you to read Larry’s book, and Gert’s review.
Gert clearly gained some new perspectives from Larry’s book. But Gert is still somewhat skeptical about some of the underlying tenants of Larry’s book. Especially when it comes to what are the major evolutionary forces that dictate how the human genome evolves. Gert makes many valid points about the over-emphasis on neutral theory, to the extent that an independent observer would think that the only important component in eukaryotic evolution, according to Larry, is the fixation of alleles by random nearly-neutral drift. Gert goes on to write:
It is the non-junk DNA that keeps us alive. Simply the fact that there is 9 times more junk than functional DNA, does not prove that the 90% is the most important part. It may be that natural selection has no power over the 90%, but it rules over the 10%. And the 10% is the most important part of our genome. Thanks to the 10% we have rather unique brains. We are the only species that invented science and write books and blogs. Thanks to the 10%. Apparently, the junk burden is compatible with life. For now. We are not alone, salamanders and lungfishes have much more junk DNA in their genomes. Junk DNA is not cancer. Junk DNA doesn't make us sick. Even Einstein must have had 90% junk DNA in his genome! Nobody ever died of junk DNA, etc. etc. etc.
So Gert’s point is spot on. It’s just that Larry’s book focuses on the 90% of the genome that we know is junk. Now Larry may argue that to make the issue clear we need to be provocative and keep his narrative laser-focused on junk DNA and neutral theory. To a certain extent he is right. But if we are not charitable, and state that the other 10% is where all the function lies, then our arguments are too easily dismissed by deniers. The deniers will claim that it is the neutralists who are too narrow minded, that we can never acknowledge that selection plays any role in shaping function. It is for this very reason that Motoo Kimura added this passage right at the start of the introduction of his book on Neutral Theory.
The [neutral] theory does not deny the role of natural selection in determining the course of adaptive evolution … the great majority of phenotypically silent molecular substitutions exert no significant influence on survival and reproduction and drift randomly through the species.
I don’t know for a fact that this passage had a mollifying effect on most selectionists, but according to John Maynard Smith it did* **. If people want to take you seriously, especially when advancing ideas, it is important to give a bit of room and to show by example that you are open to their arguments, while simultaneously challenging them to reexamine their own assumptions that underpin their viewpoints.
Let’s keep in mind that Larry is putting forth a challenge to two distinct groups.
The first group consists of the 90% of researchers in the life sciences. Their adherence to a panselectionist view point (i.e. that Evolution = Natural Selection) is due simply to the fact that they are ignorant that they are ignorant. Just getting them to realize that there is more than natural selection when it comes to evolution, would be a great advance.
The second group, in which (I think) Gert belongs, consists of individuals that are a bit more knowledgeable. They know that neutral theory exists, but (to paraphrase SJ Gould) place it in a small box that can be safely ignored. For this group making more forceful arguments, while conceding that natural selection is important, demonstrates that despite this charitable stance, we still arrive to the same conclusion. It destroys the argument that neutralists are simply polemicists. At the end of the day we want to advance not just our side, but a more balanced and insightful viewpoint that places both the selectionist and neutralists perspectives in proper proportion. If you can show that having a more balanced view can advance new insightful ideas, then that makes for a strong argument. I have tried to do so – arguing that when natural selection is dampened, and neutral processes are more rampant, this gives rise to conditions that may explain the emergence of complexity.
I do have other thoughts about Gert’s review, but I’ll leave that for another post.
*Leaving aside the fact that this passage many have been due in some part to James Crow, (according to John Maynard Smith).
**And to be complete, we are also ignoring the fact that neutral theory likely applies to some phenotypic traits as well.