Saturday, 5 September 2015

The Peppered moth controversy

I follow a blog that discusses evolution-creationism arguments and has a 'creationist wisdom' feature.  Most recently, the blog looked at an editorial in the Dalton Daily Citizen.

In this editorial,the author mentioned Pepper Moths and complained that the moths were pinned or glued to trees for the photos.
And you might also check out the textbook peppered moth story — dead moths being affixed to a tree trunk in order to stage photographic “proof” of evolution. The list goes on and on.
I can only imagine the author thinks photographing butterflies and moths is easy.  I've been lucky a few times but many times have ended up running through a field with the camera ready, trying to catch up to the insect on the wing.  It never ends well.

Since the mid-1960s most Biology textbooks have included the story of the peppered moth, accompanied by Kettlewell's two photos (or ones very similar to them). The ubiquity of the images made it that much more shocking when the public learned the photos were staged. Finding black and white moths posed beside each other in a natural setting would have been almost impossible, so to create the photos Kettlewell pinned dead moths to tree trunks. Moth experts knew the photos were staged because live moths would not have had extended wings. But no textbook ever disclosed this detail to readers.
The thing about the peppered moths study is it simply shows small-scale evolution, the sort creationists claim to accept.  Look at changes in peppered moth colouration or changes in maturation in cod or tusk length in elephants and you see the beginnings of a transition.  Look at ring species like salamanders in the Western US or gulls species about the north pole and you see a bigger step.  Genetics and fossils show the larger scale steps.  For creationists to complain about peppered moths is to see their inconsistency - "Micro evolution is okay, but this micro evolution must have been faked."  Which is it?
Added a few hours later:
Paul Braterman has a wonderfully detailed account of the history of Peppered Moth research.