By Bernard Wood
Silvana Condemi and Ger-Christian Weniger’s 2011 edited volume (Continuity and Discontinuity in the Peopling of Europe, Volume 1) commemorating the 150th anniversary of the discovery of the Neanderthal 1 skeleton contains many interesting papers. But for those of us who knew Clark Howell, the verbatim record of his plenary presentation at the conference held in Bonn in 2006 is particularly poignant for it was likely his last major public statement before his death in 2007. Sensibly, the editors decided not to edit the recording of Clark’s address, so the text of the talk captures Clark’s unique speaking style, especially his tendency to reminisce and to go off on a tangent. Fortunately for us, Clark Howell’s academic career spanned a time when intellectual giants lived on the earth, so his recollections of people (e.g., Julian Huxley, Franz Weidenreich), places and events (e.g., the 1950 Cold Spring Harbor Symposium) provide us with a metaphorical ringside seat from which we can observe the post-WWII goings-on in evolutionary biology in general and in paleoanthropology in particular. I knew much of this from sitting during long plane journeys listening to Clark reminisce, but I had never before heard him refer to Conrad Waddington.
Now there is a man I would like to have met. He was a genuine polymath, part theoretical biologist, part embryologist and geneticist and part philosopher, who positively brimmed with important new ideas, especially about development. His peers were people of the stature of Bateson, Needham and Bernal, and like many of his contemporaries he put his considerable intellect to work at the service of the Allied war effort during WWII. Waddington was among the first researchers to recognize the need to meld genetics with embryology and many of his insights made in a pre-molecular world are now the bread and butter of what today we call ‘evo-devo’. It was Waddington who coined the terms epigenesis and canalization. The powerful visual metaphor for development known as the epigenetic landscape was also his brainchild.
Canalization was introduced by Waddington in 1942 to describe the tendency for developmental processes to result in a similar phenotype despite different genetic and environmental influences. In the epigenetic landscape model, which came later, the development of an individual organism is likened to a ball rolling across a three-dimensional landscape consisting of crests and valleys. The topography of the landscape is determined by genes and, according to Waddington’s metaphor, mutations can affect the phenotypic outcome of a particular genotype by shifting either, or both, of the mean (the locations of valleys) and the variance (the steepness of the sides of the valleys) of that phenotypic outcome.
But what makes Waddington one of my heroes is his exhortation that all of us should be deeply suspicious of the hegemony of what he termed the ‘conventional wisdom of the dominant group’. When students ask about possible thesis topics I encourage them to pick something that is taken for granted and go back and look at the primary evidence to make sure that the assumptions we are making are justified.
Waddington had a wicked sense of humor; his near-acronym for the ‘conventional wisdom of the dominant group’ was ‘cowdung’.