We are often told that the science on Darwinism is settled. Advocates of academic freedom urge that teachers be allowed to challenge students and encourage critical thinking skills by sharing scientific strengths and weaknesses of evolutionary theory — “teach the controvery,” in other words. Darwin defenders respond with expressions of disbelief. The theory has no weaknesses, they say, and no controversy exists.
There might be minor disputes at the fringes, but no scientist doubts the certainty of Darwinian evolution. We can see them now, nodding in agreement: “Evolution itself has long since passed out of the field of scientific controversy,” as William Patten of Dartmouth opined in 1930. “There is no other subject on which scientific opinion is so completely unanimous. It is the one great truth we most surely know.”
How about the controversy over the central tenet of Darwinian evolution?
Nothing could be more central to Darwinian evolution than natural selection. It was in the title of Darwin’s Origin. It is the major “mechanism” along with random mutation that comprises neo-Darwinian theory. Natural selection and Darwinian evolution are inseparable. But what does natural selection mean? What entity does natural selection act on? It’s a controversy that has raged since 1859.
One current battle, showing no sign of abating, is between the kin selectionists and the group selectionists (see Casey Luskin’s play-by-play call in 2011 here and Denyse O’Leary’s post-skirmish analysis in 2015 here). Kin selectionists think that natural selection favors genes of related individuals. The idea, also called inclusive fitness, purports to explain self-sacrifice in animals and humans — why worker ants serve the queen without reproducing themselves, and why humans put themselves in danger for their families. Some of their genes, presumably, will be passed on through their kin. Kin selection theory was given a mathematical formulation by W. H. Hamilton in 1964, to the relief of many Darwinians eager to find an explanation for altruism. It was promoted by E.O. Wilson, father of sociobiology (which led to evolutionary psychology), Richard Dawkins, father of Selfish Gene theory, Jerry Coyne, and many other Darwinians.
But when E.O. Wilson jumped ship in 2004, expressing doubts about the empirical evidence for kin selection, his former friends turned on him. Wilson had joined forces with mathematicians who cast doubt on “Hamilton’s Rule” undergirding the theory. When Wilson, with Martin Nowak and Corina Tarnita criticized kin selection as empirically lacking in 2011 in Nature, 150 other evolutionists banded together to defend it, attacking Wilson’s motivations and arguments. There’s been a standoff ever since.