Jerry Coyne has celebrated Amazon’s offer of a free Kindle version of James Shapiro’s Evolution: A View from the 21st Century by asking for comments on the book. (Beware: some people seem to have been charged for their download!) Coyne hasn’t read it himself, but says that Shapiro is “heterodox in his views.” He should know, since they are both at the University of Chicago. Even so, “heterodox” seems an odd choice of words.
I actually used it in a previous post and probably shouldn’t have, as the 6th in the BioLogos series has now appeared, drawing back from hyperpreterism (though some of the commentators do not). Nevertheless my context was theological, regarding “the doctrine handed down once for all by the apostles.” That’s also the predominant sense in my dictionary, where the word is opposed to “orthodox”, meaning “in harmony with what is authoritatively approved, conventional.” It does admit of a wider sense, “holding correct or the currently accepted opinions, not heretical or independently-minded or original.”
In what sense, then, is Shapiro heterodox, since science has no orthodoxy but evidence, which is always open to review? Maybe one of the repliers, Joe G, has it when he says:
Shapiro is a teleological wolf in philosophical clothing as far as I can tell.
After all John Wilkins, in another review, says:
Shapiro is returing to the older style of teleology that might have satisfied an Aristotelian … they engaged with the best philosophical arguments of the day (and let there be no mistake, this is a philosophical claim being made, not a scientific one).
Wilkins then enters a discussion in which he says engineers do not accomplish defined functional goals, which provokes considerable disagreement from actual engineers. Nevertheless the objections to Shapiro seem to be about his interpretation more than the evidence he presents, and particularly with his underlying philosophy.
This would seem to be a valid point (if not necessarily a valid criticism). Shapiro sees the same range of mechanisms for extensive genome reorganisation that others see. They happily incorporate them into the accepted Neodarwinian framework as relatively unimportant and, in any case, still describable in terms of “variation random with regard to fitness, acted on by natural selection.” He, however, sees natural selection as minor, and these mechanisms as used “deliberately” by cells to adapt their genomes to new situations – they have evolved to evolve. No doubt further evidence would help decide between these philosophies, but at the same time philosophy will decide what evidence is to be sought, as well as how it is understood.
This is exemplified in a recent paper which describes how placentation in mammals arose from over 1500 new genes, controlled by transposons. In discussing the paper the senior author Gunter Wagner, at least, considers that the system arose suddenly rather than in small mutations accumulating over time, though the word “saltation” does not escape his lips. “In the last two decades there have been dramatic changes in our understanding of how evolution works,” he says in words reminiscent of Shapiro. The article goes on:
Intriguingly, note the researchers, the expression of these genes in the uterus is coordinated by transposons, essentially selfish pieces of genetic material that replicate within the host genome and used to be called junk DNA.
Well, they still are in respectable circles. But the lead author, Vincent Lynch, speaks more carefully:
“Transposons grow like parasites that have invaded the body, multiplying and taking up space in the genome…These transposons are not genes that underwent small changes over long periods of time and eventually grew into their new role during pregnancy. They are more like prefabricated regulatory units that install themselves into a host genome, which then recycles them to carry out entirely new functions like facilitating maternal-fetal communication.”
Now the received wisdom is that transposons are basically viral elements parasitising cells, “selfishly”. But viruses themselves are, by many, thought to have arisen from cells, so are they best seen as malignant entities that are sometimes accidentally useful, or as outsourced genetic information co-opted by cells to help in the work of adaptation (and that sometimes cause harm)? It’s an odd selfish parasite that facilitates, in one go, a vastly superior method of reproduction. Indeed it’s a very inventive and hard-working parasite that acts as a prefabricated regulatory unit.
It’s more than tempting to suspect an organised process is involved, rather than random mutation. And given the felicitous outcome, the whole sophisticated placental mechanism coded by 1532 genes, it’s even more tempting to suggest that some kind of teleology is involved.
What would the evidence suggest, if unlike James Shapiro in his heterodoxy, one were to avoid any philosophical presuppositions?