It must have seemed terribly ironic to late University of Cambridge evolutionary biologist Michael Majerus, after dedicating nearly half a century to the study of peppered moths (Biston betularia), that in the late 1990s his name became central to an increasingly contentious campaign to strip the peppered moth of its status as the prime example of Darwinian evolution in action.
It’s a well-known story: The moth’s ancestral typica phenotype is white with dark speckles. In the decades following the Industrial Revolution, a new, soot-colored form, known as carbonaria, flourished and displaced the typica moths in the heavily polluted woodlands of Europe.
Although scientists hypothesized as early as 1896 that the increase in carbonaria frequency could be explained simply by the fact that soot-covered tree barks camouflaged the dark-colored moths against predation by birds, it wasn’t until the 1950s that an Oxford University lepidopterist named Bernard Kettlewell performed the key experiments ...
