Dynamics and evolution of biological and social networks

Genetic Similarity Networks in Populations and in Metapopulations

Author: Emilio Hernandez-Garcia, IFISC (CSIC-UIB).

Names and affiliation of other authors:
A. F. Rozenfeld(2), S. Arnaud-Haond(3,4), V.M. Eguíluz(1), E. Serrão(3) and C. M. Duarte(2)
(1) IFISC, Instituto de Física Interdisciplinar y Sistemas Complejos (CSIC-UIB), Campus Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain.
(2) IMEDEA (CSIC-UIB), Instituto Mediterráneo de Estudios Avanzados, C/ Miquel Marqués 21, 07190 Esporles, Mallorca, Spain.
(3) CCMAR, CIMAR-Laboratório Associado, Universidade do Algarve, Gambelas, 8005-139, Faro, Portugal
(4) IFREMER, Centre de Brest, BP70, 29280 Plouzané, France

Oral presentation

The development of evolutionary theory in the framework of population genetics has undergone major progress with the arrival of molecular biology and molecular markers. Some major gaps have been identified between natural populations and theoretical models based on assumptions, such as panmixia, that are seldom realized in nature. Novel tools of analysis, free of most of the traditional theoretical assumptions, are needed for taking full advantage of the huge amount of information available in modern genetic data sets.
Here we use recently introduced networks of genetic similarity (A.F. Rozenfeld et al., J. Roy. Soc. Interface 4, 1093, 2007) to analyze the hierarchy and organization of the genetic diversity of a marine plant Posidonia oceanica, across its entire geographical range. On the one hand, we characterize population substructure by constructing networks in which nodes are genotypes. The networks are of the small-world type, and clustering measures indicate strong correlations not easily detectable by other means.
On the other hand, we characterize the pattern of genetic relationships among populations by constructing networks of genetic similarity in which the nodes are plant populations. Betweenness-centrality and degree-distribution calculations allowed to identify some geographical regions acting as major hubs relaying gene flow in the metapopulation system.

Dynamics and evolution of biological and social networks. February 18-20th, 2008. Mallorca, Spain.