Dobzhansky: natural selection cannot explain the origin of first life
Published: 17 January 2007 (GMT+10)
Theodosius Dobzhansky (1900–1975) was one of the leading evolutionists of the 20th century, and an ardent materialist despite a Russian Orthodox upbringing. In commenting on the origin of life, he firmly rejected theorist who invoked natural selection as an explanation, because this requires pre-existing life:
In order to have natural selection, you have to have self-reproduction or self-replication and at least two distinct self-replicating units or entities [therefore] Prebiological natural selection is a contradiction of terms.
Dr Schramm’s introduction gives me an opening for making a few remarks on my own. Natural selection is sometimes described as a mechanism capable of realizing the highest degree of improbability, as Dr Schramm has quite correctly pointed out. I would like, however, to express the belief that the words ‘natural selection’ must be used carefully. Dr Schramm has so used them. In reading some other literature on the origin of life, I am afraid that not all authors have used the term carefully. Natural selection is differential reproduction, organism perpetuation. In order to have natural selection, you have to have self-reproduction or self-replication and at least two distinct self-replicating units or entities. Now, I realize that when you speak of origin of life, you wish to discuss the probable embryonic stages, so to speak, of natural selection. What these embryonic stages will be is for you to decide. I would like to plead with you, simply, please realize you cannot use the words ‘natural selection’ loosely. Prebiological natural selection is a contradiction of terms. [Emphasis added]
- Dobzhansky, T.G., ‘Discussion of Synthesis of Nucleosides and Polynucleotides with Metaphoric Esters’, by George Schramm, in Fox, S.W., ed., The Origins of Prebiological Systems and of Their Molecular Matrices, Proceedings of a Conference Conducted at Wakulla Springs, Florida, pp. 309–310, 27–30 October 1963, Academic Press, NY, 1965.