Natural and human-mediated drivers of microevolution in Neotropical palms: a historical genomics approach

Abstract

Microevolution in Amazonia has been far less documented than in temperate regions and still constitutes a major knowledge gap. Moreover, the actual influence of pre-Columbian societies through the Holocene remains uncertain, although it could provide interesting insights on the relationship between natural and human-mediated evolutionary processes in driving microevolution. Because they are widespread and traditionally managed since pre-Columbian times, Neotropical palms are choice models to investigate the drivers of microevolution in Amazonia. In this study, we carried out a preliminary exploration of the genomic diversity in two pairs of congeneric palm species in French Guiana (Astrocaryum spp. and Oenocarpus spp.). We built upon an original sampling design taking into account both regional climate variations and local-scale pre-Columbian occupation, and carried out an extensive target capture experiment and next-generation sequencing of hundreds of palms. We explored patterns of genomic diversity and differentiation within and across populations, bringing state-of-the-art knowledge about the roles of climate adaptation and of pre-Columbian domestication. By documenting original cases of 'incipient' domestication, our results further open new avenues toward a better understanding of microevolution in Amazonia and of the impacts of pre-Columbian societies in having shaped present-day patterns of biodiversity.