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Tuesday, July 05, 2022

The State of Evolutionary Theory

Evolutionary theory: A dog's diner of notions.  But then real life is a bit of a dog's diner!

Evolutionary theorists are ill at ease it seems - mostly with one another: In a post which appeared on evangelical atheist's blog, PZ Myers, he expresses his impatience at the "Extended Evolutionary Synthesis" movement. See here:

Not impressed by the Extended Evolutionary Synthesis (freethoughtblogs.com)

This post by Myers was in response to a Guardian article entitled "Do we need a new theory of evolution?" .  This article starts with the headline paragraph:

A new wave of scientists argues that mainstream evolutionary theory needs an urgent overhaul. Their opponents have dismissed them as misguided careerists – and the conflict may determine the future of biology

....and goes on to say somewhat sensationally (My emphases on the use of emotive terms). 

Behind the current battle over evolution lies a broken dream. In the early 20th century, many biologists longed for a unifying theory that would enable their field to join physics and chemistry in the club of austere, mechanistic sciences that stripped the universe down to a set of elemental rules. Without such a theory, they feared that biology would remain a bundle of fractious sub-fields, from zoology to biochemistry, in which answering any question might require input and argument from scores of warring specialists.

...the stress, then, is on internal conflict. Myers' gripe with the article seems be this: Evolutionary theory, probably necessarily, is a complex stew of diverse theoretical elements and will likely remain so; in fact there may be yet more elements to be added to the theory to enhance its comprehensiveness: I think I agree; unlike physics I very much doubt evolutionary biology is going to reduce to those overarching grand narratives conveyed by elegant equations. Given this context Myers therefore sees the EES pundits as not necessarily being wrong but simply adding to the stew of ideas. Where the problem seems to lie is in the competitive contention that so frequently surrounds social status ladder climbing: May be because the EES aficionados are being a little too melodramatic they (whether intentionally or not) are effectively positioning themselves as heroic paradigm breaking revolutionaries and this apparent career move has stirred up hard feelings and controversy among traditionalists.  If you don't want to cause a storm of hard feelings one's social status is something best left to the judgment of others whose opinions effectively confers one's social status; DIY status conferment is certainly not advised; it will upset all sorts of people (see Luke 4:9-11).  But there is little one can do if conflicting communities confer on an individual entirely different status values....Jordan Peterson's following has raised him up to the heights of social glory which needless to say absolutely peeves PZ Myers and his associated community. 

Having said all that, however, according to Myers the article does partly redeem itself toward the end where we can read:

What Doolittle and like-minded scientists want is more radical: the death of grand theories entirely. They see such unifying projects as a mid-century – even modernist – conceit, that have no place in the postmodern era of science. The idea that there could be a coherent theory of evolution is “an artefact of how biology developed in the 20th century, probably useful at the time,” says Doolittle. “But not now.” Doing right by Darwin isn’t about venerating all his ideas, he says, but building on his insight that we can explain how present life forms came from past ones in radical new ways.

The computational biologist Eugene Koonin thinks people should get used to theories not fitting together. Unification is a mirage. “In my view there is no – can be no – single theory of evolution,” he told me. “There cannot be a single theory of everything. Even physicists do not have a theory of everything.”

People trained in physics and mathematics like myself are inclined to be instinctively be repelled by "postmodern" ideas of a patchwork of pragmatic little narratives that are here today and gone tomorrow.  Physicists are used to looking for and finding over-arching elegant theories that all but clear the theoretical board: Given the glorious highly progressive intellectual history surrounding Newton, Maxwell, Einstein, Schrodinger, Heisenberg, Dirac and Feynman et al, who can blame them? The expectation in physics therefore is that the apparent incommensurability between gravity and quantum mechanics will one day be fixed. 

But there is no reason why such should be true in biology. Biology, being a kind "natural" technology, may follow the model of own technology in that it consists of a complex of techniques and tools that are invoked in different connections.  But in spite of that there is no need to go all postmodern about this departure. Biology is still a rational system if rather more algorithmically complex than was at first hoped by the authors of the neo-Darwinian-synthesis.

***

As I've said several times before anyone who believes that the natural history of life to be spread over millions if not billions of years automatically accepts evolution in the trivial sense that life has changed and developed over that time, although via unspecified mechanisms. Natural history by itself leaves the engine driving evolutionary change unspecified. In fact even if one accepts the notion of common descent and that genetics is taken as evidence of the cladistic nesting of life forms developed from the "tree of life", the question remains as to the agency/processes/mechanisms that have generated this tree of life.  

In my mathematical "spongeam" metaphor of natural history I use the "potential" term "V" to represent what some might call the "fitness landscape" of evolution. This term could hide any number of informational factors ranging from the laws of physics, through teleological influences to ad-hoc divine patches, all factors (if present) we've yet to fully understand. If evolution is to work, the random agitations encapsulated in the diffusional term of my mathematical metaphor must be highly constrained by the information implicit in the term "V".

Myers may well be right about evolution being a kind of dogs dinner of processes. But to me he looks as though he's caught in the usual dualistic linguistic trap. Viz: if it can be said that "evolution did it" then that must imply "God didn't do it". If  all the ingredients thrown into the stew simply fall under the nomenclature of "evolution" that, for some, is enough to satisfy the metaphysical conclusion that "if evolution did it, God didn't do it".  Myers' thinking is as much trapped by the connotation of deism in the label "evolution" as is the thinking of the de facto IDists who simply reverse the sign of the conclusion: Viz "Evolution can't do it, therefore God did it". De facto ID has committed itself to the same connotative dualistic verbalism; they can't see that the very introduction of intelligent creation introduces a huge wild card which means that the possibilities open to intelligent action breathes new life into the possibilities open to the processes "evolution"; who can tell how a practically omnipotent omniscient intelligence can resource "evolution" informationally? The de facto IDists have also painted themselves into a corner with their commitment to the absence of Junk DNA; for in introducing the wild card of a super intelligence they really can't be sure what such an inscrutable & powerful intelligence would leave in or edit out of his DNA libraries. Although like John Polkinghorne I'm strictly speaking a Intelligent Design Creationist, I dissociate myself from the stuck-in-a-rut de facto ID right-wingers who are a faction within a politically polarized community. They can't see the implications of intelligent creation but have in fact unconsciously taken on board crypto-deist and dualist categories. With their politics and their philosophical categories, de facto IDists have walked down a blind alley.

***

Reading the Guardian article I was fascinated with the evolutionary ingredient called "plasticity".  Here's how the article described it:

Emily Standen is a scientist at the University of Ottawa, who studies Polypterus senegalus, AKA the Senegal bichir, a fish that not only has gills but also primitive lungs. Regular polypterus can breathe air at the surface, but they are “much more content” living underwater, she says. But when Standen took Polypterus that had spent their first few weeks of life in water, and subsequently raised them on land, their bodies began to change immediately. The bones in their fins elongated and became sharper, able to pull them along dry land with the help of wider joint sockets and larger muscles. Their necks softened. Their primordial lungs expanded and their other organs shifted to accommodate them. Their entire appearance transformed. “They resembled the transition species you see in the fossil record, partway between sea and land,” Standen told me. According to the traditional theory of evolution, this kind of change takes millions of years. But, says Armin Moczek, an extended synthesis proponent, the Senegal bichir “is adapting to land in a single generation”. He sounded almost proud of the fish.

The crucial thing about such observations, which challenge the traditional understanding of evolution, is that these sudden developments all come from the same underlying genes. The species’s genes aren’t being slowly honed, generation by generation. Rather, during its early development it has the potential to grow in a variety of ways, allowing it to survive in different situations.

Plasticity doesn’t invalidate the idea of gradual change through selection of small changes, but it offers another evolutionary system with its own logic working in concert. To some researchers, it may even hold the answers to the vexed question of biological novelties: the first eye, the first wing. “Plasticity is perhaps what sparks the rudimentary form of a novel trait,” says Pfennig.

If these observations aren't misconstrued then who knows what influence is being applied here to drive this rapid adaptive change.