@article {Tobler442830, author = {Michael Tobler and Zachary Culumber}, title = {Parent-offspring conflict, ecology, and life history diversification of livebearing fishes}, elocation-id = {442830}, year = {2018}, doi = {10.1101/442830}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Major shifts in life history evolution{\textemdash}lsuch as the transition from pre- to post-fertilization maternal provisioning in viviparous organisms{\textemdash}require complex morphological and physiological adaptations. The conditions under which these transitions arise remain largely unexplored. Theory postulates that parent-offspring conflict can drive diversification in maternal provisioning strategies, but while alternative hypotheses focusing on sexual selection and ecological adaptation have been proposed, neither have been evaluated comparatively. Livebearing fishes (Poeciliidae) have provided important insights into life history evolution due to variation in maternal provisioning strategies, mating systems, and ecology. Comparative analyses of temporal dynamics across 94 species revealed that repeated shifts from lecithotrophy (pre-fertilization provisioning) to matrotrophy (post-fertilization provisioning) preceded concomitant changes in sexual selection, establishing a previously missing causal link in the correlated evolution of life history and mating systems. Adaptive hypotheses of matrotrophy evolution were supported by correlations between ecological variables and the extent of post-fertilization provisioning. Consistent with theoretical models, matrotrophy was associated with environments exhibiting high primary productivity and low competition. In contrast, results did not support strictly conflict-driven scenarios of matrotrophy evolution. Bi-directional evolution along the lecithotrophy-matrotrophy continuum contradicted the expectation of intraspecific Red Queen dynamics with perpetual increases in post-fertilization provisioning. Our results demonstrate that parent-offspring conflict alone is not sufficient to explain the evolution of matrotrophy, but may play a role in conjunction with ecological mechanisms. We propose that natural selection mediated by resource availability counterbalances conflict-fueled{\textemdash}potentially maladaptive{\textemdash}increases in matrotrophy.}, URL = {https://www.biorxiv.org/content/early/2018/10/16/442830}, eprint = {https://www.biorxiv.org/content/early/2018/10/16/442830.full.pdf}, journal = {bioRxiv} }