Thursday, August 21, 2014

Evolution as Development and the Demise of Darwin's Natural Selection Theory

The inhumanities of the Holocaust swept from public view the until-then popular cause of eugenics. But before World War II eugenics thrived as a civic cause in the United States and the United Kingdom. Improving human stock through selective breeding and the sterilizing, or even the euthanizing, of the "unfit" had come to be regarded widely as scientifically sound public policy. The Wikipedia entry for "eugenics"  provides an introduction to this mostly forgotten fashion of the times, which Nazi ideology took to extremes of horror and which today is banished, at least in its overt forms, from policy discussion, though social critics continue to uncover its covert forms & see embedded video below:
Advocacy of eugenics continues under the banner of population control and similar euphemisms.

The Anglo-American eugenicists of the early 20th century invoked Darwinian natural-selection theory to gird their ideological bent. But, according to the arguments and evidence that Alan Bennett presents in "Evolution Revolution", these social engineers did not hijack Darwinism, nor twist it into service in a way to which Darwin would have objected. On the contrary, Darwin embraced the eugenicist agenda from the outset. Not only did Darwin himself promote eugenics, but the agenda's advocates also included Darwin's half-cousin, Francis Galton, who formalized the concept and propounded it as civic duty; Thomas Henry Huxley ("Darwin's Bulldog"); and Huxley's grandsons, Julian and Aldous Huxley, Julian serving for a time as president of the British Eugenics Society and Aldous sketching a blueprint for a caste society in his "Brave New World."

The objective of the Darwinian offensive was twofold, as Bennett summarizes:
  1. Cast the working class in the role of the unfit. 
  2. Denigrate religion. 
This history, the dark heart of Darwinian theory, presented in thoroughly referenced detail, makes up the first major portion of the book.

But the anti-Darwinian angle of Bennett's argument unwinds in a complicated way and extends beyond discrediting the motives of Darwin and his acolytes. That is, the attack is not merely ad hominem. Bennett establishes it as a point of historical fact that the concept of "descent with modification" had been around for some time prior to Darwin. Victorian society was not hostile to the idea of evolution, which it saw as evidence of God's wisdom, in His having crafted natural law so as to give rise to the diversity of life.

Neither was the mechanism of natural selection original with Darwin. It too was a concept familiar to Victorian scientists. But natural selection failed to gain traction as a scientific idea, before Darwin and his propagandists took up the cause, because the scientists of the day perceived that it was inadequate to account for the diversity of life. Under the influence of an optimizing mechanism, such as natural selection, they reasoned, phenotypes should converge, not diverge, with the passing of generations.

Natural selection theory never has rested on solid scientific evidence or reasoning. Although, by appealing to statistics and common prejudice, Darwinians grafted onto natural selection theory the trappings of a science. As a result, the sequentially amended theory became almost infinitely elastic in its capacity to absorb anomalous findings. It managed consistently to re-describe "how nature works" in ways contrived to preserve a niche for itself in the explanatory scheme. From the time Charles Darwin foisted it upon the world, natural selection theory effectively served the ideological ends of diverse brands of racists and elitists, despite its lack of scientific rigor.

However, if we follow Bennett in rejecting natural selection as the primary engine of evolution, then we are left with a process minus any explanation as to how it works. We still have to account for evolution's particular outcomes. Bennett proposes to fill the void, but the mechanism that he nominates to serve as evolution's centerpiece arrives with its own baggage.

One thrust of Bennett's revision of evolution theory borrows from ideas that competed early on with Darwin's own. The author combines the structuralist approach of Darwin's contemporary and rival, Richard Owen, with the "Lamarckian" approach of Jean-Baptiste Lamarck. This hybrid model has much to recommend it.

Naturalist Richard Owen ascribed the particulars of evolutionary change to natural laws (endogenous factors); whereas Lamarck ascribed the particulars to heritable changes in an organism that are caused by environmental stresses (exogenous factors). Bennett presents a history of these ideas, then summarizes:
"As we saw, the idea that the natural world emerged through a process of 'self-development,' or 'self-organization,' had been gestating in Western thought for over 2,000 years, stretching from Owen and the 'structuralists' to Aquinas, Augustine and on back to Aristotle and the ancient Greeks."
The Lamarckian component of Bennett's integration keeps this "self-organizing" process from being wholly deterministic. Environmental contingencies impinge on organisms, influencing their bodies and/or behavior, with some of these changes being heritable. This is Lamarckism. During much of the history of evolution theory, biologists dismissed the Lamarckian model, a standard argument against it referencing the blacksmith's arm: Are the blacksmith's children born with one conspicuously developed arm? But Lamarckian effects can in some cases be observed, and new findings in the field of epigenetics provide an ostensible mechanism whereby acquired traits might be passed on to offspring. So, the door has opened to re-introduce Lamarckian thought to evolutionary theory.

In Bennett's model, evolution is an unfolding of inherent potential that absorbs or reacts to the environment's influences. And so evolution, or phylogeny, in his formulation takes on the character of development, or ontogeny. This parallelism is touched upon in the book but not developed thoroughly. We will return to it after examining Bennett's case from a broad perspective, that of complexity theory.

Bennett recruits complexity theory to serve as a general, overarching framework within which to understand evolutionary change. By situating evolution in the context of complexity theory, Bennett minimizes distinctions between biology and other sciences, which maybe is as it should be. Here is language typical of that which he uses to characterize his view of how nature works:
"In an unfolding sequence, quarks, guided by nothing more than the relationships between themselves, form atoms, which in time organize themselves into stars, solar systems and entire galaxies. These naturally developing relationships formed increasingly complex patterns which held the information for making stars, planets and eventually entire galaxies. These patterns contained the information for making the universe complex."
I share the author's conclusion that something is missing from evolution theory, that natural selection cannot do what it is supposed to do, and that some other mechanism is needed to pull up the slack. But I do not share Bennett's faith that the building blocks of complexity theory —emergence, patterns, relationships, self-assembly and other abstractions, as he constellates them—will do the job satisfactorily. Explanations in terms of patterns, self-organization, etc., smell like disguised appeals to vitalism, which is the notion that an undetectable, animating "life force" or similar construct accounts for biological processes. Vitalism long has been discredited as a scientific idea, but now it's back, camouflaged by the quasi-technical argot of complexity theory. Bennett writes, "Emergence is one manifestation of an even more transforming concept about nature: immaterial things can bring material things into existence. [. . . .] This is the third key to the new understanding of evolution: much of nature and evolution emerges from immaterial things, like relationships, and patterns."
It's not clear what such contentions bring to the table. Explanations of the particulars of the physical world in terms of gravity, thermodynamics, fluid flow, radiation, kinetics, and so on—normal scientific concepts—lend themselves to units of measure, to being quantified. Complexity theory offers no units of measure. And its reliance on "immaterial" causes makes it akin to a theology.

Nor does complexity theory articulate the necessary and sufficient conditions under which an assembly of parts will organize itself spontaneously into a self-regulating complex system. Sometimes it happens and sometimes it doesn't? And how can patterns, or relationships, be causal agents? I would argue that patterns and relationships are what we observe after causal agents have acted.

In short, complexity theory begs the question as to whether it explains what it purports to explain in terms of causality or just describes what is observed.

Nonetheless, complexity theorists claim vast explanatory powers that transcend biology to include everything from the particulars of chemistry and cosmology to sociocultural organization. The borders among the disciplines get fuzzy. A kind of conceptual freefall accompanies the adoption of complexity theory, and this is particularly highlighted when we pry natural selection theory from evolution.

Natural selection theory attached itself specifically to the biological world, not to other areas of science. The other disciplines don’t get jostled when it gets abandoned, nor when it gets replaced by complexity theory. But, once the peculiar mechanism of natural selection is set aside, what is left to distinguish biological evolution from other kinds of successive change? Without natural selection, is "evolution" just a multisyllabic synonym for "change"? Does biology become just another process that expresses the principles inherent in complexity theory?

Maybe so. And I am glad to join Bennett in discarding biology's specialness as a natural kind. But Bennett is not as vigilant as he ought to be in retaining distinctions among certain processes internal to biology's vast, ongoing complexification. He is out to proffer a totalizing metanarrative that accounts for change. But in doing so, he tends to gloss over distinctions among evolution, development, and plain old change. He would seem not to think that there was much difference in meaning among statements such as, "Look, that complex system is organizing itself" and "Look, that thing over there is developing" and "Look, that thing over there is evolving."

The difference between the latter two characterizations is critical. It must not be swept aside. To use evolution and development more or less interchangeably, as Bennett tends to do, muddies the waters precisely where clarity is needed, if we are trying to sort out the causal mechanisms that produce the particular outcomes that we observe. Consider this passage:
"The daunting challenge for Darwinists is this: if evolutionary change in every science - physics, chemistry, cosmology, geology and all the others - is predictable, why would evolution in biology be unpredictable? If the evolution of atoms, molecules, minerals, stars, planets, continents, mountains and oceans are [sic] predictable, why would the evolution of plants and animals suddenly be unpredictable?"
The processes inherent in the other disciplines don't qualify as instances of evolution, at least not in the usual sense of multigenerational descent with modification. But they might, so long as we're stretching definitions, qualify as instances or processes of development. Let's back up.

The word development attaches itself, for example, to the sequence that runs, egg >> hatchling >> hen. The egg-to-hen sequence is influenced genetically in a way that predisposes it to unfold in a predictable sequence: the process has a preferred direction. Given an accommodating environment, the internal energetics of a chicken proceeds along a predictable path. That's how development works.

The sciences have to deal with change, per se, of various kinds. But the term “evolution,” as specific to Bennett’s chosen target, biology, typically isn't used to designate change per se, but change of the type specifically that occurs during a sequence of generational turnovers. It's not clear how the normal usage of "evolution" would apply to the quarks of physics, the molecules of chemistry, or the mineral formations of geology.

That said, most readers, I suspect, will want to maintain distinctions among the related notions of evolution, development, growth, assembly, and just plain change. It's not clear that Bennett sees value in maintaining these distinctions.

In this light, consider that, as it has come to be used, "evolution," as distinct from "development," designates a nonteleological process. That is, the evolutionary process is taken by scientific officialdom to proceed without a preferred direction. It is extemporaneous and not developmental. Development, on the other hand, is predictable. It proceeds, so long as the environment accommodates it, along a preferred direction, toward the adult form of the species. It has a teleological character as it unfolds in its predictable sequence.

Bennett's other point in the passage cited earlier has to do with natural selection theory’s lack of forecasting prowess. And Bennett rightly points out that if natural selection theory were properly scientific, then it would lend itself to making predictions that were more than trivial. Because it doesn't do much by way of making predictions, it doesn't lend itself to falsification, weakening its status as a scientific theory.

Darwinian Theory, through all of its variously evolved forms, certainly failed to predict the intriguing findings that have come out of genomic sequencing and subsequent cross-species genomic statistical comparisons. The conservation of DNA across species? That was a stunning finding, at which a scientific theory of evolution might at least have hinted. But no. Did textbook evolution theory get ANYTHING right in this regard? If the theory is supposed to account for gene distributions, then why did it fail so miserably when given the chance to prove itself? Did natural selection theory belly up to the bar and say, "Well, now that you have the technology to sequence genomes and conduct detailed cross-species statistical analyses on the resulting databases, let me tell you beforehand what observations you shall make." No. It did not belly up. It sat on the sidelines, mute, unable to articulate anything that would vouchsafe itself as a usefully predictive tool of science. Natural selection theory? Bah-humbug.

If we take the ball from Bennett and run with it, emphasizing the developmental character of evolution--as an endogenously driven process, being variously facilitated and constrained by its environment--and re-categorize it explicitly as an instance of development, then we introduce implications that Bennett might not want to see commingling with his ideas. Namely, we imply that the evolution of life on Earth constitutes a succession of stages in the life cycle of an organism, with the ensuing teleological implications.

Framing evolution as a developmental process preserves the elements that Bennett wants to include in his revised theory and gathers those elements under a familiar heading: Development. Insofar as it simplifies the conceptual scheme and claims bragging rights to parsimony, re-classifying evolution as an instance of development is a move that leapfrogs natural selection theory to propose a more scientifically credible hypothesis.

But this move raises more questions. What is the adult form of a developing planetary biosphere? And, once we show up--we high-tech primates--do we have any obligations to the historical/developmental process? Are we obliged to play any kind of predetermined role in the unfolding of the historical program? As the zygote harbors the adult, does the caveman, or the amoeba for that matter, harbor the space colonist? And, if so, can creatures refuse their callings, and what happens if they do? The developmental model of evolution forces into the open issues of historical meaning, purpose, and obligation.

The foregoing remarks might seem to arrive from far out in left field, but they are of the moment. As endogenous factors continue to infiltrate evolutionary theorizing, evolution increasingly looks like an instance of development. If the theory continues in this direction, then at some point the notion of "life cycle" will need to be scaled up and applied to planetary biospheres. And then humankind's cosmic calling will assert itself as the elephant in the room, we must hope.

Admittedly, this review presents only an overview of an ambitious book. My copy is dog-eared from much note-taking, as I found the ideas and references presented required mindful consideration, page after page. The book delivers a wealth of insight into the history of evolution theory, (the retelling of the story of Ota Benga, the pygmy displayed in New York's Bronx Zoo in 1906, with a chimpanzee for a companion, reminds us of Darwinian theory's racist utility), documenting the gyrations that the theorists put the theory through with each new problem that scientific discovery threw at it. The anomalies continue to pile up, however, and if Thomas Kuhn got it right in The Structure of Scientific Revolutions, then natural selection theory's elasticity at some point will give way, with a conceptual SNAP, and scientists will be left to assemble a new evolutionary paradigm, one that we must hope will be devoid of utility to racists.