Bad takes #1. We have long known.
Unfamiliar ideas are often mis-identified and mis-characterized. It takes time for a new idea to be sufficiently familiar that it can be debated meaningfully. We look forward to those more meaningful debates. Until then, fending off bad takes is the order of the day! See the Bad Takes Index.
An anonymous reviewer responded to the manuscript of Stoltzfus and Yampolsky (2009) with the claim that “we have long known that mutation is important in evolution,” citing the following passage from Haldane (1932) as if to suggest that the message of our paper (emphasizing the dispositional role of mutation) was old news:
A selector of sufficient knowledge and power might perhaps obtain from the genes at present available in the human species a race combining an average intellect equal to that of Shakespeare with the stature of Carnera. But he could not produce a race of angels. For the moral character or for the wings, he would have to await or produce suitable mutations
We included it in the final version of the paper because, actually, this passage demonstrates the opposite of what the reviewer implies. What is Haldane suggesting?
I can’t resist a good story, so let’s begin with this 1930s photo of Italian boxer Primo Carnera, his friend and fellow heavyweight champ Max Baer, and Hollywood actress Myrna Loy. Baer dated Loy in real life. They made a movie together, the three of them (thus the staged publicity photo). Baer, one of the greatest punchers of all time and half-Jewish, became a hero to a generation of Jewish sports fans when he demolished Max Schmeling, the German champion, prompting Hitler to outlaw boxing with Jews. He literally killed one of his opponents, and repeatedly sent Carnera to the floor during their single fight.
But the point of this picture is that, although Baer was a formidable man, Carnera makes him look small. Other fighters were afraid to get in the ring with him. Though enormous — 30 cm taller and 50 kg heavy than the average Italian of his generation —, Carnera was not the aberrant product of a hormonal imbalance. This photo shows a huge man who is stocky but well proportioned, muscular, and surprisingly lean. Again, he was not a misshapen monster, but a man at the far extremes of a healthy human physique, which is precisely Haldane’s point.
Selective breeding to the quantitative extremes of known human ability, Haldane proposes, could produce a race combining the extreme of Carnera’s magnificent stature with Shakespeare’s magnificent verbal ability.
Haldane contrasts this with a different mode of evolution dependent on new mutations, which might produce a race of angels, if one could wait long enough for the mutations to happen. That is, Haldane is contrasting (1) a mode of evolution that could combine the known extremes of human ability with (2) a mode of evolution that could generate imaginary fictitious not-at-all-real creatures. Haldane, Wright and Fisher each argued that a mode of change dependent on new mutations would be too slow to account for the observed facts of evolution. They argued instead that evolution must take place on the basis of abundant standing variation.
That is, in the passage above, Haldane is not endorsing a mode of mutation-dependent evolution, but gently mocking it, in contrast to a mode of evolution that, based on quantitative standing variation, could produce a race of magnificently eloquent champions.
Thus, the reviewer’s comment was a bad take on Haldane, a misinterpretation of Haldane’s meaning.
In addition, the “we have always known” comment represents a more general category of bad take that substitutes, in place of a specific target of criticism, a much broader, fuzzier, or more generic claim. Note what the reviewer does not say: the reviewer might have said
“The authors’ implicit claim of novelty is preposterous. We have long known about the role of biases in the introduction process emphasized in this manuscript. Haldane (1932) and Fisher (1930) explored the theoretical implications of such biases, and Simpson and Mayr repeatedly incorporated a theory of internal variational trends into their interpretations of the fossil record. The authors must cite these sources instead of suggesting that their arguments are original.”
But of course, the reviewer does not say this, because nothing like this ever happened. Think about it.
Certainly, the reviewer is correct that scientists in the mainstream Modern Synthesis tradition have always known that mutation is important in evolution. More precisely, the importance they assigned to mutation was that it is ultimately necessary, because without mutations, evolution would grind to a halt. Haldane, Fisher, Ford, Huxley, Dobzhansky, and others said this explicitly.
However, they did not say that mutation is important as a dispositional factor. Instead, they argued explicitly against this idea, e.g., Haldane (1927) is the original source of the argument that mutation pressure is a weak force (see Bad takes #2).
The theory of biases in the introduction process, by contrast, says that mutation is important in evolution as a dispositional cause, a cause that makes some outcomes more likely than others, and that this importance is achieved (mechanistically) by way of biases in the introduction process.
So, the reviewer is making an implicit bait-and-switch argument. The theory of biases in the introduction of variation is a specific population-genetic theory with specific conditions and implications, and the reviewer is responding to this by saying “we have always known that mutation is important,” but this is not the same thing: the traditional importance assigned to mutation is not “dispositional cause that makes some outcomes more likely than others” but “ultimate source of raw materials without which evolution would grind to a halt.”
Finally, this bad take is part of a family of bad takes in which the novelty of a claim X is rejected on the grounds that X sounds vaguely like X’, or that X can be categorized as a member of some larger and fuzzier class of claims (see Bad Takes #5: Contingency). This is often the case with “we have long known” arguments. If the theory was in fact old, the reviewer would not have made a vague “we have long known” argument, but would have cited the original source of the theory, e.g., “Of course the theory of biases in the introduction process is not new, because Haldane proposed exactly the same theory 70 years ago and worked out its implications!” In fact, no such antecedent exists, which is why, to defend tradition, the reviewer must resort to a bait-and-switch argument.
References
Haldane JBS. 1932. The Causes of Evolution. New York: Longmans, Green and Co.
Stoltzfus A, Yampolsky LY. 2009. Climbing mount probable: mutation as a cause of nonrandomness in evolution. J Hered 100:637-647.