Manfred Eigen in his book Steps Toward Life (Oxford University Press 1992) makes it clear that the science of complex. systems is helping us understand how biology and evolution work. For example, genes today did not arise randomly. Mutation of genes can seem random, but it is clear now that a “process of optimization” works towards functional efficiency.
A series of changes in gene sequence is stabilized by selection. Mutation or environmental changes can set off a “cascade of changes” that overwhelm stable intermediate states. Since “selection is based on self-replication,” it “distinguishes sharply between competition, thus [steering] the entire complex system” of a life form.
Changes in environment can produce better adapted variants, if a “rich spectrum” of mutations occurs just below the number of mutants that a system can tolerate. This gives the system stability that is flexible, so that the highest rate of evolution occurs. In a very cold environment, where the energy supply is iffy, this could make the appearance of life difficult. Astrobiology may need something extra, namely an actively changing environment.
Since life systems are very complex, quantitative predictions of outcome are impossible. We can’t project the results of a changing environmental experience on an ecosystem, according to Eigen. He goes on to explain that if a species’ genes have 300 mutations there could be 4300 possible sequences spread over a wide and variable landscape of genetic portraits.
He notes that a rise of successful mutants is not a function of quality. Superior mutants arise by a sequence of causes: First, a wild type error produces a close relative of that wild type.
When a rare large mutation occurs that has selective advantage, preferred states of that rare mutation are selected so that intermediates produce very different mutants from the wild type.The mutant spectrum becomes wide in the possible landscape of genetic patterns with superior mutants occurring in the mountainous regions of that landscape. That is, superior mutants occur with more frequency.
When one superior mutant on the periphery collapses, the established ensemble collapses and a new ensemble arises around the superior mutants. There higher peaks can be expected since efficient mutants occur on such ridges. As a result, superior mutants are tested with higher probability.
So what’s the point? Selection occurs on the entire ensemble of mutants.
The process of species survival is not due to random mutation on a wild type. Thus, Eigen argues against neo-Darwinism in that regard. He believes there is directedness in evolutionary processes. If change in species over time is due to natural selection, it is value oriented, not random.
In earlier essays, we have talked about the need for thermodynamic change to drive early life. This fits with Eigen’s genetic analysis.
Apparently, changes in environment are needed to impact the landscape of genetic patterns that define and direct new life forms so that they can try out new features and do a better job of surviving.
What environments Out There, besides Earth’s, are constantly changing?
Author of The Archives of Varok
The View Beyond Earth (Book 1. Rewrite of A Place Beyond Man 1975)
The Webs of Varok (Book 2.)
Nautilus silver award 2013 YA
ForeWord finalist 2012 adult SF
The Alien Effect (Book 3.)
An Alien’s Quest—Reconciliation and Hope (Book 4. coming in 2015)
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