Fake Darwinism in an International Test of Experimental Evolution
Darwin’s blunder lives on. In the Origin, he famously confused artificial selection with natural selection.
Slow though the process of selection may be, if feeble man can do much by artificial selection, I can see no limit to the amount of change, to the beauty and complexity of the coadaptations between all organic beings, one with another and with their physical conditions of life, which may have been effected in the long course of time through nature’s power of selection, that is by the survival of the fittest. [Emphasis added.]
The two kinds of “selection” are poles apart. The former has an aim, a goal, a purpose. The latter is blind. It doesn’t care what happens. The organism can go extinct, for all nature knows (which is nothing, because nature is not a mind). Critics have long complained that “natural selection” is an oxymoron, and “survival of the fittest” is a tautology (see Darwin’s House of Cards by Tom Bethell, Chapter 5). Yet today still, 160 years after Darwin’s blunder, many evolutionary biologists still don’t get the distinction.
“The Evolthon Challenge”
Welcome to “The Evolthon Challenge,” a spectacular case of Darwin’s blunder published in PLOS Biology. Dozens of scientists joined in an effort to refine the effectiveness of “experimental evolution.” The contest would have been fine if they had just left Darwinism out of the picture, and explained that they were intentionally seeking preferred results out of random variations, but they repeatedly confused what they were doing with what “nature” does.
In experimental evolution, scientists evolve organisms in the lab, typically by challenging them to new environmental conditions. How best to evolve a desired trait? Should the challenge be applied abruptly, gradually, periodically, sporadically? Should one apply chemical mutagenesis, and do strains with high innate mutation rate evolve faster? What are ideal population sizes of evolving populations? There are endless strategies, beyond those that can be exposed by individual labs. We therefore arranged a community challenge, Evolthon, in which students and scientists from different labs were asked to evolve Escherichia coli or Saccharomyces cerevisiae for an abiotic stress — low temperature. About 30 participants from around the world explored diverse environmental and genetic regimes of evolution. After a period of evolution in each lab, all strains of each species were competed with one another. In yeast, the most successful strategies were those that used mating, underscoring the importance of sex in evolution. In bacteria, the fittest strain used a strategy based on exploration of different mutation rates. Different strategies displayed variable levels of performance and stability across additional challenges and conditions. This study therefore uncovers principles of effective experimental evolutionary regimens and might prove useful also for biotechnological developments of new strains and for understanding natural strategies in evolutionary arms races between species. Evolthon constitutes a model for community-based scientific exploration that encourages creativity and cooperation.
Try It with Pebbles
To see the blunder, imagine doing this experiment with pebbles. Put them in the freezer, and see which ones crack. Call the ones that don’t crack the “fittest” that somehow “evolved” in an “arms race” to survive a new stress. That, of course, would be silly, but do not evolutionists consider organisms to be nothing more than physical objects, like pebbles? Cells differ from rocks by way of their internal programming that allows them to adapt. Programming always comes from a mind. The mind is not in the bacteria. The mind is not in the freezer. It had to be programmed from outside the system by an intelligent cause.
Furthermore, intelligent minds (the scientists participating in the Evolthon challenge) guided the cells toward their own preferred outcomes. To “evolve” a bacterium is to steer it, to guide it, to mold it to one’s wishes. “Natural selection” has nothing to do with it. Matti Leisola exposed the illogic of Darwin’s blunder last year in these pages:
What’s the problem? First there’s the conflation of artificial and natural selection. More fundamentally, the term “directed evolution” is a contradictio in adjecto, in the same way the term “wooden iron” is. It obscures the reality that the new enzymes were engineered via intelligent design. We’re called bioengineers for a reason, after all.
See also Michael Flannery’s comments on the distinction: “As Wallace tried to point out to Darwin, natural and artificial selections are fundamentally different.”
Learning About Bacteria and Yeast
The bioengineers in the Evolthon Challenge undoubtedly learned some things about the robustness of genetic programming in bacteria and yeast. But they did not learn anything about natural selection, because “nature” is not a selector. It has no goal. It is blind, deaf, and dumb.
Evolutionary blunders often come in bundles. Notice how this paper begins, with allegiance to Dobzhansky, Lenski, and other proponents of Darwin’s blunder.
The known saying, “Nothing in biology makes sense except in light of evolution,” clearly exemplifies the pivotal role of evolutionary thinking in biology. Classical investigations in evolution are based on observing and comparing organisms in nature, and they require inference of the past conditions and species history. Though extremely insightful, this approach can be effectively complemented by “lab-evolution,” a research paradigm in which organisms, typically microbes, are evolved in the lab. In this controlled setup, species can be challenged by changing environmental conditions, e.g., starvation, exposure to antibiotic drugs, high temperature, high salinity, or by perturbing their genes, and then they can be followed as they evolve, inspecting a diversity of physiological and genomic means of adaptation. Therefore, rather than simply observing a snapshot, an entire evolutionary “movie” can be followed, during which the environment is not only known but can also be controlled and manipulated. The Long Term Evolutionary Experiment is a famous experiment that essentially established the field, and in recent years many experiments followed.
Behe Vindicated Again
One redeeming feature of this paper is that it vindicates Behe’s “first rule of adaptive evolution” explained in Darwin Devolves: i.e., “Break or blunt any functional gene whose loss would increase the number of a species’ offspring.”
Evolution often trades off between competing tasks. For example, when improving fitness towards a certain challenge under selection, organisms might compromise their fitness in another environment, in particular the original environment to which they were already adapted….
The behavior of the “Variable mutation-rate selection” strategy across the conditions was interesting. Although this strategy performed the best under the designated low temperature conditions, it did worse in the other, unforeseen challenges. This behavior might indicate that a mutagen can be beneficial in finding a good genetic solution to a particular environment under selection but might compromise other parts of the genome that are presently not under selection but that might prove crucial in the future.
The winning “polar bear bacteria” got by in the freezer, but lost genetic information in the process. As usual, this paper says nothing about the creative power of natural selection to create novel designs requiring irreducibly complex specified information. The adaptations involved genetic loss — devolution. The distinction is lost on these dozens of scientists:
One can be very creative in designing an evolutionary experiment, and the number of degrees of freedom is essentially unlimited. Post factum, one could ask, how did the evolutionary strategy employed affected performance? For example, it has been shown in yeast that exposure to an abruptly applied challenge, high temperature, as opposed to incremental increase in the temperature, pushed cells to evolve very different solutions. When exposed to an abrupt increase in temperature, yeast evolved through aneuploidy, a solution that proves to be maladaptive in other stresses, and that might not endure well after short relaxation periods. Therefore, an interesting possibility is that the adaptation regime applied during evolution would affect the stability and generality of the adaptation.
How can one link these kinds of adaptation to natural selection? Yet, they do. Intelligent researchers in the lab, with minds and goals steering everything,
…would have carried out an orderly experiment with appropriate controls in which a whole range of concentrations were examined. However, natural evolution actually works the “Evolthon way” in the sense that genomes never evolve by systematically varying their parameters over a range of potential values (say, expression level of a gene or affinity of an enzyme to a substrate). Instead, evolution tries out sporadic solutions and continues with the fittest. In that respect, we might say that here we apply the nature of the evolutionary process to the study of evolution itself.
If they were really applying “the nature of the evolutionary process to the study of evolution itself,” they would have had to turn off their minds. The mind makes all the difference. A mind is a terrible thing to waste.
Photo: Saccharomyces cerevisiae (brewer’s yeast), by A doubt [CC BY-SA 3.0], via Wikimedia Commons.