Unifying Theories of Molecular, Community and Network Evolution

1 The origin of diversification and coexistence of genes and species have been 2 traditionally studied in isolated biological levels. Ecological and evolutionary 3 views have focused on the mechanisms that enable or constrain species coexis4 tence, genetic variation and the genetics of speciation, but a unified theory linking 5 those approaches is still missing. Here we introduce evolutionary graphs in the 6 context of neutral theories of molecular evolution and biodiversity to provide a 7 framework that simultaneously addresses speciation rate and joint genetic and 8 species diversities. To illuminate this question we also study two models of evo9 lution on graphs with fitness differences, which provide insights on how genetic 10 and ecological dynamics drive the speed of diversification. Neutral evolution gen11 erates the highest speed of speciation, species richness (i.e. five times and twice 12 as many species as compared to genetic and ecological graphs, respectively) and 13 genetic–species diversity (i.e., twice as many as genetic and ecological graphs, 14 respectively). Thus the speed of speciation, the genetic–species diversity and 15 coexistence can differ dramatically depending on whether genetic factors versus 16 ecological factors drive the evolution of the system. By linking molecular, sexual 17 and trophic behavior at ecological and evolutionary scales, interacting graphs 18 can illuminate the origin and evolution of diversity and organismal coexistence. 19