A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins

Abstract

Butterflies are a diverse and charismatic insect group that are thought to have evolved with plants and dispersed throughout the world in response to key geological events. However, these hypotheses have not been extensively tested because a comprehensive phylogenetic framework and datasets for butterfly larval hosts and global distributions are lacking. We sequenced 391 genes from nearly 2,300 butterfly species, sampled from 90 countries and 28 specimen collections, to reconstruct a new phylogenomic tree of butterflies representing 92% of all genera. Our phylogeny has strong support for nearly all nodes and demonstrates that at least 36 butterfly tribes require reclassification. Divergence time analyses imply an origin ~100 million years ago for butterflies and indicate that all but one family were present before the K/Pg extinction event. We aggregated larval host datasets and global distribution records and found that butterflies are likely to have first fed on Fabaceae and originated in what is now the Americas. Soon after the Cretaceous Thermal Maximum, butterflies crossed Beringia and diversified in the Palaeotropics. Our results also reveal that most butterfly species are specialists that feed on only one larval host plant family. However, generalist butterflies that consume two or more plant families usually feed on closely related plants.

Phylogenomics resolves major relationships of Catocala underwing moths

“…Lastly, the present study reconfirms that obtaining DNA from decades-old museum specimens is feasible (see e.g., Kawahara et al, 2023;Nunes et al, 2022). Half of our sequenced samples came from dry, pinned museum specimens and sequence capture was successful for 340 loci for a specimen of C. abamita Bremer & Grey collected at least 87 years prior to DNA extraction (Table S1).…”

“…There were no shifts observed from other host plant families to Fabaceae, which could indicate that switching to another host plant family may cause host plant specialization that renders a backshift to Fabaceae less likely. This trend is also found in butterflies (Kawahara et al, 2023), which suggests that feeding on Fabaceae may be evolutionarily beneficial, preventing future back-shifts to other larval plant family hosts. Furthermore, there were multiple examples of host plant shifts at nodes that have short leading internode branch lengths.…”

Biogeographic–tectonic calibration of 14 nodes in a butterfly timetree

“…There are no known fossils of the group studied in this paper, Coenonymphina, or of its sister, Eritina. Despite these problems, Kawahara et al (2023) used "different fossil and secondary [fossil-based] calibration schemes" in their calculation that butterflies originated "around 101.4 Ma". This date is treated here as a fossil-based, minimum clade age, not an actual clade age.…”

“…This methodology is, again, ultimately based on fossil calibration (of the plant phylogeny), and so the butterfly clade ages that are calculated using this method are minima. Nevertheless, they are often treated as maximum ages and used to rule out earlier origins (Wahlberg et al, 2009;Espeland et al, 2018;Chazot et al, 2019Chazot et al, , 2021Allio et al, 2020;Tseng et al, 2022;Kawahara et al, 2023). In any case, the age of angiosperms and their clades is currently the subject of much debate; recently proposed ages of angiosperms range from Early Cretaceous to Permian, a period of time spanning 107 Myr (Sauquet et al, 2021).…”

A Comprehensive Natural History Review of Chlosyne lacinia (Geyer, 1837; Lepidoptera: Nymphalidae): Patterns of Phenotypic Variation and Geographic Distribution

“…While much of the rapid speciation of butterflies took place in the tropics, the Melitaeini tribe, which includes the genus Chlosyne , is thought to have originated in the Nearctic (Wahlberg & Zimmermann 2000, Kawahara et al 2023). To further resolve whether Chlosyne , and Chlosyne lacinia in particular, also have a Nearctic origin, followed by geographic expansion into Mexico, Central and South America, would substantially advance our understanding of the evolutionary histories of these groups.…”