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More on Randomness in Natural Selection and Evolution

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A common objection to neo-Darwinian evolution highlights the fact that the theory is based to a large extent on chance events, or chance in general. For decades now there has been an extraordinary volume of grim polemics against that objection. I wrote about this here last week in the context of a dispute between Richard Dawkins and Stephen Meyer. To my earlier comments, I would add the following.

Referring to Waddington and Mayr, Julian Huxley 1962 also strongly believed:

The frequent assertion that biological evolution is based on chance is entirely untrue. “Chance” events furnish its raw material but the process itself is directional, self-steering, but automatically steering itself in a definite direction. This is because…natural selection is not a random but an “ordering” mechanism.

Ridley 1985, p. 124, concurred:

How can I hope to succeed with three authors (Denton, Hayward, and Pitman) who, like the Victorian astronomer Sir John Herschel, think that evolution by natural selection is the “law of higgledy-piggledy” — a “random search mechanism” (Denton), of “pure chance” (Hayward and Pitman)?

And up to the present, authors including Lorenzen, Krauss (2016), and Dawkins (2016) have made similar statements (see here for Stephen Meyer’s response to Dawkins).

Now, let’s assume for a moment that the frequent assertion that biological evolution is based on chance is itself “entirely untrue.” Assume instead that the process is, in fact, “directional” and “self-steering,” truly an ordering mechanism.

In that case, what is the biological basis for the “survival of the fittest”? The survival is very clearly dependent on the functionality of the anatomical, physiological, genetic (and more) structures, synorganized and cooperating in the organism (including its behavior or conduct), about whose origin we just asked. How did these structures and functions evolve?

A hare runs faster, a lion jumps farther, a zebra senses a carnivore better, an eagle spots prey at a greater distance, a chimp responds more effectively than his or her conspecifics. Why? Because — according to the neo-Darwinian doctrine — the chance events of mutation and recombination have equipped them as needed, with all structures originating until then as well as the newly gained improvements. All this occurs in a continuous process of evolution. Thus, chance events determine everything in evolution: form and function of all structures dominating natural selection in the struggle for life and hence the entire phylogeny of plants and animals.

There is, of course, even according to neo-Darwinian theory, no selection without form and function of already existing and subsequently improved structures. Let me emphasize: all must be generated by random micro-mutations with “only slight or even invisible effects on the phenotype.”

Hence, natural selection is in itself neither self-steering nor an ordering mechanism, etc. Instead it is the result of structures, features, forms, functions, and capabilities altogether produced by the chance events of accidental mutations alone, including the overproduction of descendants.

It is the habitual method of many supporters of the modern synthesis to disconnect or decouple natural selection from chance events, but this is totally unjustified. For me this disconnection or detachment appears to be part of a wily and widespread propaganda effort, seeking to manipulate public and scientific opinion to make neo-Darwinian evolution more acceptable and digestible. For evolution by an almost infinite series of fortunate strokes of small serendipities seems to be, prima facie, implausible to most thoughtful people.

And yet, consistent with evolution, the entire world of organisms has to be, in fact, traced back to pure chance events and random occurrences. Nobel laureate Jacques Monod seemed to belong to a minority of evolutionists who fully comprehend the consequences of the synthetic or neo-Darwinian theory. He wrote concerning mutations:

We call these events accidental; we say that they are random occurrences. And since they constitute the only possible source of modifications in the genetic text, itself the sole repository of the organism’s hereditary structures, it necessarily follows that chance alone is at the source of every innovation, of all creation in the biosphere. Pure chance, absolutely free but blind, at the very root of the stupendous edifice of evolution: this central concept of modern biology is no longer one among other possible or even conceivable hypotheses. It is today the sole conceivable hypothesis, the only one that squares with observed and tested fact. [Italics by Monod.]

Yet, Monod’s assertions on the origin of the biosphere are essentially all wrong. See here, please, for the facts and inferences in my encyclopedia article about natural selection.

References:

Huxley, J. (1962) [Book Review]: The Nature of Life, by Prof. C. H. Waddington. Pp. 131 (London: George Allen and Unwin, Ltd., 1961. Nature 194: 43-44. The full quotations reads:

Waddington proceeds to point out that the frequent assertion that biological evolution is based on chance is entirely untrue. “Chance” events furnish its raw material, but the process itself is directional-selfsteering, but automatically steering itself in a definite direction. This is because, in Ernst Mayr’s phrase, natural selection is not a random but an ‘ordering’ mechanism. It is quasi-finalistic, or, to use Pittendrigh’s useful term, “teleonomic” — it orders chance events into directional channels.

Ridley, M. (1985) [Review of 3 books]: More Darwinian Detracters. Nature 318: 124-125.

Monod, J. (1971): Chance and Necessity: An Essay on the Natural Philosophy of Modern Biology. Pp. 112-113. Random House, Inc., New York. First Vintage Book Edition, October 1972. Also see here.

Image credit: Malene Thyssen (Own work) [GFDL or CC BY-SA 3.0], via Wikimedia Commons.

Updated by W.-E. L, April 14, 2016.