Polymorphic phenotypes have long been used to examine the maintenance of genetic variation within and between species. Most studies have focused on persistent polymorphisms, which are retained across species boundaries, and their positive effects on speciation rates. Far less is known about the macroevolutionary impacts of more transient polymorphisms, which are also common. Here we investigated male wing polymorphisms in aphids. We estimated the phylogenetic history of wing states across species, along with several other traits that could affect wing evolution. We found that male wing polymorphisms are transient: they are found in only ~4% of extant species but have likely evolved repeatedly across the phylogeny. We reason that the repeated evolution of transient polymorphisms might be facilitated by the existence of the asexual female wing plasticity, which is common across aphids, and would maintain the wing development program even in species with wingless males. We also discovered that male winged morphs and wing polymorphisms are associated with higher speciation rates, and male wingedness correlates positively with host plant alternation and host plant breadth, and that winged morphs and wing polymorphisms may be associated with higher speciation rates. Our results provide new evolutionary insights into this well-studied group and suggest that even transient polymorphisms may impact species diversification rates.

This dataset uses a previously published aphid phylogeny and maps male wing states. These states were compiled from various aphid monographs, publications, private and public datasets and collections (all sourced and cited in the Supplementary References of the manuscript). They were then analyzed using phylogenetic simulations including ancestral state reconstructions, stochastic character mapping, and speciation/extinction diversification models.

All the analyses were done in R using public and published phylogenetics packages.