Polyploid plants have faster rates of multivariate climatic niche evolution than their diploid relatives

Abstract

Whole genome duplication is an important evolutionary process in plants. In contrast to other speciation mechanisms, polyploid species begin with substantial postzygotic reproductive isolation from progenitors while being sympatric with one or both. These nascent polyploid species often go extinct due to ecological and evolutionary genetic obstacles. Interestingly, polyploid species appear to quickly occupy different geographic distributions and ecological niches than their diploid progenitors. Using biogeographic data from polyploid and diploid species representing 49 genera of vascular plants, we tested whether climatic niches of polyploid species evolve faster than their diploid relatives. We found polyploid species often have less climatic overlap than expected with diploid progenitors. Consistent with this pattern, we estimated that the climatic niches of polyploid plants consistently evolved faster than the niches of diploid relatives. Our results indicate ecological niche differentiation is important for polyploid establishment, and suggest ecological differentiation is important for speciation processes more widely.