Mitochondrial Phylogenomics Resolves the Global Spread of Higher Termites, Ecosystem Engineers of the Tropics

Abstract

The higher termites (Termitidae) are keystone species and ecosystem engineers. They have exceptional biomass and play important roles in decomposition of dead plant matter, in soil manipulation, and as the primary food for many animals, especially in the tropics. Higher termites are most diverse in rainforests, with estimated origins in the late Eocene (∼54 Ma), postdating the breakup of Pangaea and Gondwana when most continents became separated. Since termites are poor fliers, their origin and spread across the globe requires alternative explanation. Here, we show that higher termites originated 42-54 Ma in Africa and subsequently underwent at least 24 dispersal events between the continents in two main periods. Using phylogenetic analyses of mitochondrial genomes from 415 species, including all higher termite taxonomic and feeding groups, we inferred 10 dispersal events to South America and Asia 35-23 Ma, coinciding with the sharp decrease in global temperature, sea level, and rainforest cover in the Oligocene. After global temperatures increased, 23-5 Ma, there was only one more dispersal to South America but 11 to Asia and Australia, and one dispersal back to Africa. Most of these dispersal events were transoceanic and might have occurred via floating logs. The spread of higher termites across oceans was helped by the novel ecological opportunities brought about by environmental and ecosystem change, and led termites to become one of the few insect groups with specialized mammal predators. This has parallels with modern invasive species that have been able to thrive in human-impacted ecosystems.

Out of the Orient: Post‐Tethyan transoceanic and trans‐Arabian routes fostered the spread of Baorini skippers in the Afrotropics

“…Studies of unrelated taxa have suggested that this passage was used as a means of dispersal. For instance, Bourguignon et al () hypothesized that multiple clades of termites (Isoptera) used this bridge to disperse between the two continents. They argued that because these termite clades were fungus‐growers, geodispersal was more likely than LDD.…”

Mitochondrial phylogenomics, the origin of swallowtail butterflies, and the impact of the number of clocks in Bayesian molecular dating

“…Full mitochondrial genomes are a data‐rich and relatively accessible source of information, and promising results have been obtained for several insect families and orders (e.g. Haran et al ., ; Simon & Hadrys, ; Timmermans et al ., , ; Bourguignon et al ., , ). But there have been few mitophylogenomic studies with comprehensive taxon sampling for butterflies.…”

Termite diversity in Neotropical dry forests of Colombia and the potential role of rainfall in structuring termite diversity

“…Samples forming a well‐supported cluster were named identically. Species names were carefully checked with available literature and correspond to those reported for Neotropical termites (Bourguignon et al., ; Cameron, Lo, Bourguignon, Svenson, & Evans, ; Casalla et al., ,b; Eaton et al., ; Inward et al., ; Roy et al., ). Voucher specimens of all species are held at the University of Freiburg, Germany, and will be deposited at the Natural History Museum of the Alexander von Humboldt Institute of Bogotá (MIAvH).…”