Introduction: E Pluribus Unum

Vidyanand Nanjundiah, Stuart A Newman
2014 Journal of Biosciences  
The 12 papers in this special issue of Journal of Biosciences are based on talks given at a discussion meeting on the theme 'Individuals and Groups' that was held in Almora from 22 to 31 May 2012. About 50 people took part, all of them as discussants and approximately half also as speakers. Not everyone who spoke contributed an article; the shortfall was made up partially by some who were unable to attend but agreed to write. These papers are a fair representation of the range of viewpoints,
more » ... ugh not systems, covered at Almora. The aim of the meeting was to explore the evolutionary basis of group behaviour in biology and discuss commonalities and differences between diverse viewpoints. A question that might provide a common theme had been suggested to the speakers: To what extent can one account for group behaviour in terms of the properties of the constituent units as exhibited when they are isolated, and to what extent does one need to invoke group-level, 'emergent' traits? As will be seen, the question is addressed in different ways, some overlapping and others in apparent conflict, by the authors of this special issue. Even though the responses concern group behaviour in biological systems, many contain indications of how the individual versus group issue is confronted in physics and chemistry. Within biology, groups at different levels of organizationgenes, proteins, metabolic pathways, cells, organisms and speciesare considered. Before introducing the papers in this issue, we offer our own perspective on individuals and groups. Until the influential intervention of Darwin and Wallace, biologists tended to adopt either a functionalist approach to the explanation of living systems, typically one (as with Cuvier) in which the purposes the functional units served were stipulated by a Creator, or alternatively, a structuralist approach (as with Geoffroy Saint-Hilaire), somewhat akin to physics and chemistry, in which organizational properties were assumed to be intrinsic to the constituent materials, and function was relatively incidental. The Darwinian revolution advanced the functionalist tradition but shifted the focus on why the traits of living organisms were what they are away from the creationist mode. It put forward an account that involved extrinsic factors the demands of the environment and natural selection, following an internal but undirected event, random variation (later tied to genetic change). Current thinking has led to a resurgence of interest in structuralist approaches, but has attempted to incorporate the major insights of a century of Darwinian functionalism. Functional (or 'proximate' or 'how') explanations in biology lean on immediately preceding events and are typically based on phenomenological physics and chemistry regarding mechanism, if not organization. Biology stands out from the other natural sciences in that it also demands a qualitatively different sort of explanation, one that is called historical or 'ultimate'. Ultimate explanations derive from the historical fact of organic evolution. Cosmology and the evolution of the chemical elements also involve history, but one that is many levels removed from the perceptible physical properties of present-day forms. It would seem odd if someone were to say 'Nothing in physics makes sense except in the light of evolution', whereas the corresponding statement was proposed by Dobzhansky as a tenet of biology. The difference is that the properties of organisms tend to be rationalized by their histories, while physical properties and laws tend to be treated as givens. In the Darwinian framework, ultimate explanations are based on natural selection, which endows them with a flavour that is unique to biology. In turn, natural selection is based on variations in organismal traits that derive from the working of genes within living matter; it acts on organisms and claims to diversify lineages and modify species. A broad consensus developed around the 1950s regarding how evolution
doi:10.1007/s12038-014-9424-1 pmid:24736151 fatcat:sb475lezfnfllj5mpasynwicv4