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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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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