Mutualistic interactions are increasingly recognized as playing
important roles in community assembly. We hypothesized that mutualisms
can influence the accumulation of evolutionary history within
communities through indirect interactions, which we investigated by
quantifying the impact of mutualism gains and losses on phylogenetic
structure in the Fabaceae family. Analyzing global distribution data, we
find that legumes lacking mutualistic interactions exhibit reduced
phylogenetic clustering, resulting in higher phylogenetic diversity in
regions richer in non-mutualistic legumes. Moreover, the probability of
a plant species being introduced to a new range is negatively related to
phylogenetic distance to its nearest native relative, but this effect is
weaker for species without mutualistic interactions. These findings
highlight the significant role of mutualism in restricting the local
distribution of evolutionary history at a global scale. Our study
advances community assembly theory and underscores the importance of
considering mutualism in the conservation and restoration of
phylogenetic diversity.