Spatial patterns in ant colonies

doi:10.1073/pnas.152302199

Spatial patterns in ant colonies

^*Laboratoire d'Ethologie et Cognition Animale, Centre National de la Recherche Scientifique, Formation de Recherche en Evolution 2382, ^‡‡Equipe Traitement et Compréhension d'Images, IRIT, and ^**Laboratoire d'Energétique, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cédex 4, France; ^‡Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501; ^§Eurobios, 9 Rue de Grenelle, 75007 Paris, France; ^¶Center for Nonlinear Phenomena and Complex Systems, CP 231, Université Libre de Bruxelles, Boulevard du Triomphe, 1050 Brussels, Belgium; and ^‖Complex Systems Group, Departament de Fisica i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Sor Eulàlia d'Anzizu s/n, Campus Nord, Mòdul B4, 08034 Barcelona, Spain

Communicated by I. Prigogine, Free University of Brussels, Brussels, Belgium (received for review January 8, 2002)

Abstract

The origins of large-scale spatial patterns in biology have been an important source of theoretical speculation since the pioneering work by Turing (1952) on the chemical basis of morphogenesis. Knowing how these patterns emerge and their functional role is important to our understanding of the evolution of biocomplexity and the role played by self organization. However, so far, conclusive evidence for local activation–long-range inhibition mechanisms in real biological systems has been elusive. Here a well-defined experimental and theoretical analysis of the pattern formation dynamics exhibited by clustering behavior in ant colonies is presented. These experiments and a simple mathematical model show that these colonies do indeed use this type of mechanism. All microscopic variables have been measured and provide the first evidence, to our knowledge, for this type of self-organized behavior in complex biological systems, supporting early conjectures about its role in the organization of insect societies.