Reticulate Evolution Everywhere Nathalie Gontier Abstract Reticulation is a recurring evolutionary pattern found in phylogenetic reconstructions of life. The pattern results from how species interact and evolve by mechanisms and processes including symbiosis; symbiogenesis; lateral gene transfer (that occurs via bacterial conjugation, transformation, transduction, Gene Transfer Agents, or the movements of transposons, retrotransposons, and other mobile genetic elements); hybridization or divergence with gene flow; and infec- tious heredity (induced either directly by bacteria, bacteriophages, viruses, pri- ons, protozoa and fungi, or via vectors that transmit these pathogens). Research on reticulate evolution today takes on inter- and transdisciplinary proportions and is able to unite distinct research fields ranging from microbiology and molecular genetics to evolutionary biology and the biomedical sciences. This chapter sum- marizes the main principles of the diverse reticulate evolutionary mechanisms and situates them into the chapters that make up this volume. Keywords Reticulate evolution · Symbiosis · Symbiogenesis · Lateral Gene Transfer · Infectious agents · Microbiome · Viriome · Virolution · Hybridization · Divergence with gene flow · Evolutionary patterns · Extended Synthesis 1 Reticulate Evolution: Patterns, Processes, Mechanisms According to the Online Etymology Dictionary (http://www.etymonline.com), the word reticulate is an adjective that stems from the Latin words “re¯ticulātus” (having a net-like pattern) and re¯ticulum (little net). When scholars identify the evolution of life as being “reticulated,” they first and foremost refer to a recurring evolutionary pattern. N. Gontier (*) AppEEL—Applied Evolutionary Epistemology Lab, University of Lisbon, Lisbon, Portugal e-mail:
[email protected] © Springer International Publishing Switzerland 2015 1 N. Gontier (ed.), Reticulate Evolution, Interdisciplinary Evolution Research 3, DOI 10.1007/978-3-319-16345-1_1 2 N.