Ultraconserved element phylogenomics reveals novel insights into the historical biogeography of euophryine jumping spiders (Araneae: Salticidae)

The Euophryini is one of the largest tribes of jumping spiders (Salticidae), with diverse morphology, ecology and behaviour, and is an important focus of systematic and evolutionary studies of jumping spiders. Notably, it is the only salticid tribe that has diversified nearly equally across both the Old and New Worlds, making its historical biogeography particularly intriguing. However, understanding its biogeography has been challenging without the application of phylogeny-based biogeographical analytical approaches. In this study, we obtained ultraconserved elements (UCEs) from 255 euophryine and 45 outgroup taxa. The UCE phylogenomics provided a reliable phylogenetic framework that strongly supports the monophyly of the tribe and the division of Euophryini into two major clades (Clades A and B). Clade A consists exclusively of Old World euophryines, while Clade B includes a radiation in the New World along with several Old World lineages. Temporal divergence analyses, utilizing known jumping spider fossils, suggest that most divergences of euophryines likely occurred post-Eocene. Biogeographical analyses indicate that Euophryini most likely originated in the Palaearctic and Indomalayan regions, followed by multiple dispersals between the Indomalayan and Australasian regions, the Palaearctic and Indomalayan regions, the Palaearctic and Nearctic regions, and the Nearctic and Neotropical regions during the Oligocene and Miocene epochs. In contrast to the previous view that early continental transitions between the Old and New World for Euophryini were facilitated by the Antarctic land bridge, our study supports the Neotropical radiation having dispersed from the Palaearctic through the Nearctic, rather than from the Australasian region via Antarctica. Findings from this study significantly enhance our understanding of the origin, and temporal and spatial divergence of euophryine jumping spiders.