The 1999 Crafoord Prize Lectures. The idea of information in biology.

Abstract

]TRANSCRIPTION, translation, code, library, message, editing, proof-readingany textbook account of molecular biology will define these terms, and any discussion among professionals will employ them. All are concerned with the transmission and storage of information. They have precise and well understood meanings in biology, and the parallels between the biological and colloquial meanings are rather close. For example, in proof-reading a copy is compared, symbol by symbol, with an original, and if any discrepancy is found the copy is altered so that it corresponds with the original. In our book, The Major Transitions in Evolution, Eors Szathmary and I (Maynard Smith and Szathmary 1995) suggested that there have been, in the course of evolution, a series of changes in the way in which information is stored and transmitted-for example, the origin of chromosomes, of the genetic code, of sex, of multicellular organisms, and of language. Each transition was the precondition for the evolution of further complexity. Few biologists, I think, would wish to disagree with this picture, although they might, with good reason, wish to argue with our account of the mechanisms underlying particular transitions. These two examples show that notions of information are now pervasive in biology. Yet, with a few honourable exceptions (e.g., Sarkar 1996; Godfrey-Smith 1999; Sterelny and Griffiths 1999), philosophers of biology either ignore the concept of information, or argue that it is irrelevant and misleading (Mahner and Bunge 1997). So, if philosophers are unwilling to analyse the notion of information in biology, it will have to be done by biologists. Jablonka (in press) has recently made such an attempt. In particular, she reviews the different mechanisms of heredity observed in the living world. This essay is my own contribution. In the main, it is a discussion of how the idea has been applied in genetics, evolution and developmental biology: I am not competent to discuss recent applications of Information Theory in neurobiology.