17 Nov 2009

Instantaneous Evolution. Creative Evolution. Bergson. Ch.1 Part 11. Devries and Sudden Variation

by Corry Shores
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Instantaneous Evolution

Henri Bergson

Creative Evolution

Évolution Créatrice

Chapter 1

The Evolution of Life – Mechanism and Teleology

Chapitre Premier

De l’évolution de la vie. – Mécanisme et finalité.

11. De Vries and Sudden Variation

11. De Vries et la variation brusque

Mechanists think that evolution happens by means of random variations. Darwin claimed that they happened slowly by “insensible variations.” Bergson discussed and critiqued this previously. He explained that a complex organ like the eye has many different coordinated parts. We cannot conceive of how each little advance was made unless the evolution presupposed some kind of organic wholeness to the eye’s function. But evolution that is guided in that way is no longer random.

Now Bergson will address the other theory of random evolution. According to this theory, there are sudden mutations. Hugo de Vries is responsible for this idea.

§68 Unlikely Leaps of the Eye

Bergson recalls the similarities between mollusk and invertebrate eyes [see §64]. Let’s begin first with the theory of insensible variations. It would say that both mollusk eyes and invertebrate eyes developed little-by-little, but each time by random. It is hard to imagine how two independent lines of develop would coincide, when each would require an incalculable number of tiny coinciding variations. So to say that both mollusks and invertebrates developed eyes by ‘sudden leaps’ makes it more conceivable that the changes were random. Bergson also discussed previously another problem with the theory of insensible variations. The eye has very many different parts. If there is a small variation in one part, without there being variations in the other, then the new variation would not better serve the eye’s functioning. And hence there would be no cause for this trait to be passed-on. But if there are sudden variations in all the parts, then we can imagine how the advance would better adapt the species to its circumstances. Yet if there was one great variation in just one part, then the eye would function more poorly. So the mutation would need to change all the parts at once. Yet this again requires that chance surmount grave unlikelihood.

§69 Correlation as Final Causation

Darwin proposed an explanation. Usually a variation of one type is accompanied by others. For example, white cats with blue eyes are also deaf. So changes are coordinated with other changes. But how would deafness aid the survival of the cat? In a sense, these changes seem dis-coordinated. But this explanation supposes that a number of concurrent changes would also be coordinated to improve functioning. However, that is only possible by means of a “mysterious principle” “whose duty it is to watch over the interest of the function” (71c). And yet, to posit such a principle is to abandon the original premise that the variations were accidental.

The theory of sudden variation is supported most by experiments in botany. But plants can take-on many different variations without that profoundly changing their functioning. So a profound change in the form of the leaf for example will not require major changes throughout the rest of the plant in order for it to maintain its proper functioning. This is not so for the more complex systems of animals, which are very easily thrown out of balance by the slightest changes.

Evolutionists often speak of correlated variations. But we see that to do so is to suppose some guiding force that coordinates the changes. That would be a form of finalism, then, even though the supposed basis is mechanistic.

From the English translation:

From the original French:

Bergson, Henri. L'Évolution Créatrice. Ed. Felix Alcan. Paris: Librairies Félix Alcan et Guillaumin Réunies, 1908. Available online athttp://www.archive.org/details/levolutioncreatr00berguoft

Bergson, Henri. Creative Evolution. Transl. Arthur Mitchell. London: MacMillan and Co., 1922. Available online at:http://www.archive.org/details/creativeevolutio00berguoft

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