Information theory broadens the spectrum of molecular ecology and evolution

Information or entropy analysis of diversity is used extensively in community ecology, and has recently been exploited for prediction and analysis in molecular ecology and evolution. Information measures belong to a spectrum (or q profile) of measures whose contrasting properties provide a rich summary of diversity, including allelic richness (q = 0), Shannon information (q = 1), and heterozygosity (q = 2). We present the merits of information measures for describing and forecasting molecular variation within and among groups, comparing forecasts with data, and evaluating underlying processes such as dispersal. Importantly, information measures directly link causal processes and divergence outcomes, have straightforward relationship to allele frequency differences (including monotonicity that q = 2 lacks), and show additivity across hierarchical layers such as ecology, behaviour, cellular processes, and nongenetic inheritance. Diversity of molecules or species is best summarised as a diversity profile.Such profiles are useful in studies spanning bioinformatics to physical landscapes.Shannon information is a neglected but particularly informative part of the profile.Shannon now has robust theoretical background for molecular ecology and evolution