Mendelian-Mutationism (II): The Fluctuation-Mutation Distinction

As discussed in my last post, the mutationist/Mendelians (defined below) have mostly been sidelined in the history of biology. The claims used to justify this argument make up what Arlin Stoltzfus and I call “The Mutationism Story.” While Arlin first discovered this in the scientific literature, we found that scientists were getting many of these mistaken claims from historians and philosophers!

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Mendelian-Mutationism (I): The Forgotten Synthesis

tl;dr: I am published!

What did early geneticists such as William Bateson, Hugo de Vries, Thomas Hunt Morgan and R.C. Punnett contribute to evolutionary thought? Nothing, according to many scientific sources. They aren’t included in various timelines of the history of evolutionary biology and most are not included in the Oxford Encyclopedia of Evolution. When they are mentioned with regard to evolution, they are depicted as fools who missed the big picture, rejected natural selection, and developed a dead-end “mutationist” alternative to Darwinism.  The standard story is that clear and reasonable thinking about evolution vanished for a generation— the so-called “eclipse of Darwinism”—, returning with Fisher, Haldane, Wright, et al., who showed that genetics is the missing piece of Darwin’s theory, resulting in the Modern Synthesis.

This is wrong.

The first geneticists made substantial contributions to the theory of evolution, even though history has generally not recognized their achievements. Following their critique of Darwinism (next post), the Mendelians (Bateson, Punnett, Morgan, etc.) synthesized genetics with natural selection, laying down the foundations for later evolutionary theorizing. This post illustrates some of these developments.

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“Experimental Evolution Amongst Plants” (1895)

Tl;dr: This post features my (thus far) favorite quote that I have found when doing historical work on experimental evolution. In his speech/article, Liberty Hyde Bailey argued that the truth of evolution had already been demonstrated… centuries ago as well as in the present day, not by the academic elite, but by those involved in the cultivation of fruits, vegetables, and flowers. For Bailey, the domestication of plants and animals was a form of experimental evolution.

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The Historical Importance of Modularity

I am currently sitting in on a graduate philosophy of biology seminar and the theme of this semester’s seminar is evo-devo and we recently discussed the concept of modularity. I’m also sitting in on a history of biology course and we have talked a little about the early 19th century French scientist, Georges Cuvier. While attending the seminar, I was delighted to make a historical link between the two! (And oddly enough, one of the works we read in the seminar was a chapter from a book on modularity co-authored by Gunther Wagner which opens with the same link I had made.)

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Ants and Their Castes in the Spencer-Weismann Controversy

Wikipedia: Meat eater ant feeding on honey

Ant (Wikipedia)

Ants are evolutionarily weird and are quickly rising in my favorite organisms list.  The same evolutionary principles apply to ants as they apply to us, of course, but because ants are haplodiploid, live in large colonies, and have a caste system, biologists have to apply the same principles differently – it isn’t exactly intuitive. Ants (and other insects such as bees and termites) are frequently the subjects of hot debate when it comes to kin selection, but their role in evolutionary disputes is over a century old. Charles Darwin discussed them in The Origin of Species, but they were later the center of the controversy between Herbert Spencer and August Weismann.

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Wait. What? Herbert Spencer was a Lamarckian?

While reading Peter J. Bowler’s The Eclipse of Darwinism, I was surprised to find out that the “social Darwinist”* Herbert Spencer was actually more Lamarckian than Darwinian. He apparently expressed Lamarckian views prior to the 1859 publication of The Origin of Species, and while he accepted Darwinian explanations and the theory of natural selection, Spencer believed Lamarckism – defined (here) as the inheritance of acquired characteristics through use/disuse – was the more important of the two theories. In fact, in his article, “The Inadequacy of Natural Selection,” Spencer states quite strongly that “either there has been inheritance of acquired characters, or there has been no evolution” (621).

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When the developmental context changes, so do the master controllers

In my last post, I mentioned that I was reading Cycles of Contingency: Developmental Systems and Evolution and while I will highlight its major themes in a later post, I wanted to again briefly focus on one of its essays that I found fascinating. Developmental biologist H. Frederik Nijhout’s essay “The Ontogeny of Phenotype” (based on a 1997 paper) primarily argues that developmental pathways cannot be isolated from their genetic background, i.e., context matters, and the integration of developmental networks are also not cast in stone. There is a potential and remarkable fluidity to developmental systems that I was not previously aware of.

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“Niche construction” before “niche construction” was cool?

One of the most useful aspects of being aware of the history of science is that much like literature and the arts, one can trace the historical origins of ideas and make connections among various thinkers who lived at different times. Last week’s post was a great example of such a connection: the arguments of Gould & Lewontin were articulated over 70 years before 1979 by TH Morgan, and more astoundingly, William Bateson (who even nailed down the idea of a “spandrel”). While there may be no link between Gould & Lewontin and Morgan & Bateson, this example shows us that biologists have had to argue against adaptationism since at least 1903. We can see a clear historical trend.

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Allele Origination by Intergenic Recombination (Adaptive Recursion IV)

ResearchBlogging.orgNew alleles are normally said to arise from mutations, but recombination can be just as potent. Recombination relies on new mutations, of course, but its shuffling power increases the number of possible allele combinations. Biologists Jeffrey Feder and Sebastoam Velez found that the Jamaican click beetles use recombination to generate their unique bioluminescent polymorphisms, but this recombination is between two different, but related, genes, and creates a novel allele cycling system.

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“Spandrels” before “spandrels” were cool

In 1979, Stephen Jay Gould and Richard Lewontin famously attacked what they called the “Adaptationist Program.” They accused evolutionary biologists and sociobiologists of concocting “just-so stories” in which scientists would claim a particular trait, an adaptation, was a result of natural selection without rigorously testing their hypotheses. If they did test the claim and it turned out the claim was false, the scientist would create another just-so story, rarely questioning whether the trait was an adaptation or possibly a byproduct or fixed by non-adaptive processes. Most readers are familiar with this argument, so I won’t expand any further.

Upon reading material for my history major paper, I came across some arguments by the biologists T.H. Morgan and William Bateson that seemed oddly familiar…

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