Darwin Day Lecture 2004

2004 February 12, London School of Economics

Dr Michael Majerus, moth expert and leader of the evolutionary genetics group at Cambridge University, gave a passionate and witty defence of the Peppered Moth to a packed lecture hall at the London School of Economics.

The Peppered Moth has long been the classic text book example of observable Darwinian evolution: changes in the moth’s coloration in response to industrial pollution, later reversed in response to the cleaner air of the late 20th century, have been widely observed and explained by the effects of bird predation on survival and breeding.

Majerus related how, ironically, it was his 1998 book Melanism: Evolution in Action that triggered criticisms of earlier work on the Peppered Moth and the naturalists involved in it, beginning with an inaccurate review in Nature by Jerry Coyne. He entertainingly described his shock and dismay at the misquotations and sensationalism that followed, and their exploitation by creationists in stories such as "The Piltdown Moth".

He then took the audience through the mistakes and misconceptions of the critics, and evaluated the possible explanations of the data. But his conclusion was that the Peppered Moth remains the best visible example of rapid Darwinian evolution, and also that the strength of Darwin’s theory does not depend only on the Peppered Moth – there are many other less visible examples such as the rapid evolution of antibiotic-resistant bacteria. He conceded that better, more natural, observations were needed to provide definitive proof, and although these are difficult and time-consuming, he expects results from his fieldwork in a couple of years – and he expects to see them on the front cover of Nature, whatever they show. ‘Why does all this matter?’ Majerus wondered at one point, and answered his own question by referring to the urgent need understand science properly if we are to solve the problems of over-population and threats to our eco-system. Those that teach creationism in science lessons or who write pseudo-science threaten that vital understanding.

The evening had begun with chair Professor Richard Dawkins’ tribute to Darwin’s theory of natural selection – "the most powerful explanation ever of life on this planet – and probably on other planets too" – and ended with questions from the audience, thank-yous, and a reception, kindly provided by LSE's interdisciplinary Institute of Management.

This was the second Darwin Day lecture organised by the BHA, and the first with sponsorship from the Interdisciplinary Institute of Management and the help of Dr Satoshi Kanazawa , for which we are very grateful.

Read the complete lecture The Peppered Moth Controversy : the decline of a Darwinian Disciple.

After the 2004 lecture Dr Majerus accepted the BHA's invitation to become a Distinguished Supporter of Humanism. He wrote:

I am flattered to be invited to join the Association's list of 'Distinguished Supporters of Humanism', and I am very happy to accept. Our earth faces huge problems of overpopulation, diminishing resources, loss of habitats and species extinctions. More than ever before, biologists with an understanding of the complexities of ecological systems are needed. Darwinian evolution is fact. And as the great Russian/American geneticist, Theodore Dobzhansky famously said, "nothing in biology makes sense except in the light of evolution". Only through understanding of the complexities of natural systems do we have a hope of successfully addressing the monumental problems we face.