bioRxiv preprint doi: https://doi.org/10.1101/530477; this version posted January 26, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Evolution of life cycles and reproductive traits: insights from the brown algae 2 Svenja Heesch1*, Martha Serrano-Serrano2*, Rémy Luthringer1, Akira F. Peters3, Christophe 3 Destombe4, J. Mark Cock1, Myriam Valero4, Denis Roze4, Nicolas Salamin2§, Susana Coelho1§ 4 5 1Sorbonne Université, UPMC Univ Paris 06, CNRS, Algal Genetics Group, Integrative Biology of Marine 6 Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France. 2Department of Ecology and 7 Evolution, University of Lausanne, 1015 Lausanne, Switzerland 3Bezhin Rosko, 29250 Santec, France. 8 3Bezhin Rosko, 29250 Santec, France. 4Evolutionary Biology and Ecology of Algae, CNRS, Sorbonne 9 Université, UC, UACH, UMI 3614, 29688 Roscoff, France. 10 11 *These authors contributed equally to this work. 12 §correspondence:
[email protected];
[email protected] 13 ABSTRACT 14 Brown algae are characterized by a remarkable diversity of life cycles, sexual systems, and 15 reproductive modes, and these traits seem to be very labile across the whole group. This 16 diversity makes them ideal models to test existing theories on the evolution of alternation 17 between generations, and to examine correlations between life cycle and reproductive life 18 history traits. In this study, we investigate the dynamics of trait evolution for four life-history 19 traits: life cycle, sexual system, level of gamete dimorphism and gamete parthenogenetic 20 capacity. We assign states to up to 70 species in a multi-gene phylogeny of brown algae, and 21 use maximum likelihood and Bayesian analyses of correlated evolution, taking phylogeny into 22 account, to test for correlations between life history traits and sexual systems, and to 23 investigate the sequence of trait acquisition.