Egenis seminar with Professor Paul Griffiths 'Lehrman’s dictum: Information and explanation in biology'
Professor Paul Griffiths, Egenis and the University of Sydney
University of Exeter,Egenis,Byrne House,St Germans Road,Exeter, EX4 4PJ
Room no: GF7
Time: 3:00 - 4:30pm
Developmental psychobiologist Daniel S. Lehrman wrote that, “although the idea that behavior patterns are ‘blueprinted’ or ‘encoded’ in the genome is a perfectly appropriate and instructive way of talking about certain problems of genetics and evolution, it does not in any way deal with the kinds of questions about behavioral development to which it is so often applied.” (Lehrman, 1970: 35). According to Lehrman, it is legitimate to regard the genome as a means for the transmission of information from parent to offspring, but not to explain the development of phenotypic traits as the expression of genetic information. There is something prima facie puzzling about this claim– if the reason offspring resemble their parents is the transmission of information, then surely that information explains the development of the trait in the offspring?
Lehrman’s dictum has recently been challenged by philosopher of biology Nicholas Shea, who argues that the information transmitted from parent to offspring in the genome is ‘read in development’ and that the inheritance of this information explains developmental outcomes (Shea 2007, In Press). Shea’s application of ‘infotel semantics’ is a significant advance on previous attempts to use the idea of information to analyse the relationship between evolutionary and developmental explanations. It identifies a class of questions which have been neglected in previous accounts of explanation in biology. But it does not support the idea that inherited information is ‘read in development’. In an important sense, Lehrman is still right.