Résumé
This thesis investigates the evolutionary history of Indonesian nutmegs (Myristica fragrans and M. argentea), which are spice tree species native respectively to the Moluccas Archipelago and Papua Island. We explored the influence of the environment and human utilization on the evolutionary history of the two species. Based on a large sampling covering both native and introduced populations of the two species and using a set of complementary molecular markers (newly developed microsatellite markers, chloroplast genome sequences and nuclear genes), we investigated (i) the geographical origin of M. fragrans, its divergence in its native range and its introduction history; (ii) the impact of climate change, effect of topography and human utilization on the evolutionary history of M. argentea in Papua Island. Our findings revealed that M. fragrans originated from the South Moluccas, and that human activities most probably contributed to a reduction of population size of the species. Most of the introduced populations were sharing genetic similarities with the South Moluccas, suggesting that this later region was a primary source of propagation material along the introduction history of the species. Further, our results suggest that the evolutionary history of M. argentea in Papua Island was shaped by past climate change, mountain ranges and riverine networks. Introduced populations of M. argentea were mainly sourced from one native population in South Fakfak. This study provides insights into the evolutionary history of M. fragrans and M. argentea, informing conservation strategies and addressing environmental challenges.