Victory By Definitional Fiat

Evolution News & Views:

The National Research Council’s report — The Limits of Organic Life in Planetary Systems — is a must read. Not for the science — what there is of it can be summed up simply: we have no clue how life began. No, the report is a must read for the insight it offers into the current state of origin of life research:

For generations the definition of life has eluded scientists and philosophers. (Many have come to recognize that the concept of “definition” itself is difficult to define)… Indeed, because the chemical structures of terran biomolecular systems all appear to have arisen through Darwinian processes, it is hardly surprising that some of the more thoughtful definitions of life hold that it is a “chemical system capable of Darwinian evolution.”

Aside from jargon that would make Derrida squirm— “the concept of definition is itself difficult to define”— the Council claims to see, through post-modern haze, a more thoughtful definition of life: life is defined as “a chemical system capable of Darwinian evolution”! This more thoughtful definition of life is an even grander tautology than 'survivors survive': Darwin’s theory must explain life because life is defined as ‘what Darwin’s theory explains.’ You've got to admire the audacity.

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The natural tendency toward terracentricity requires that we make an effort to broaden our ideas of where life is possible and what forms it might take. Furthermore, basic principles of chemistry warn us against terracentricity. It is easy to conceive of chemical reactions that might support life involving noncarbon compounds, occurring in solvents other than water, or involving oxidation-reduction reactions without dioxygen. Furthermore, there are reactions that are not redox. For example, life could get energy from NaOH + HCl; the reaction goes fast abiotically, but an organism could send tendrils into the acid and the base and live off the gradient. An organism could get energy from supersaturated solution. It could get relative humidity from evaporating water. It is easy to conceive of alien life in environments quite different from the surface of a rocky planet. The public has become aware of those ideas through science fiction and nonfiction…

Mostly fiction. The Council's report is necessarily written in the subjunctive tense. There isn't a shred of evidence for "non-terracentric" life. The Council is unsure even about explanations for terracentric life. They point out the inadequacy of Darwin’s theory to explain biological complexity. The Council barely stops short of signing on to the Dissent from Darwinism list, which is a list of scientists (over 700 now) who agree with the statement: "We are skeptical of the claims for the ability of random mutation acting on natural selection to account for the complexity of life." The Council admits, with surprising candor:

Natural selection based solely on mutation is probably not an adequate mechanism for evolving complexity. More important, lateral gene transfer and endosymbiosis are probably the most obvious mechanisms for creating complex genomes that could lead to free-living cells and complex cellular communities in the short geological interval between life’s origin and the establishment of autotrophic CO2 fixation about 3.8 billion years ago...

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If the only explanation that you have for specified complexity in nature is materialistic, then without Darwinism you have no explanation at all. The wild speculation by origin of life researchers and astrobiologists isn’t gratuitous; it’s necessary. It’s the only way to explain the origin of life within the limits of their ideology. Wild speculation is the best they can do. It’s all they can do.

Perhaps we, like the Council, ought to construct our outlook by exploiting a strategy to embrace our ignorance and define life without terracentricity, defining life as Darwinian while at the same time recognizing that the concept of definition itself is difficult to define (I’m getting the hang of it!). Perhaps life arose via silicon chemistry, or via energy fields, or via supersaturated solutions, or via sodium hydroxide and hydrochloric acid gradients or… whatever. Heck, we can’t even define life, but it’s Darwinian!