A collaborative backbone resource for comparative studies of subterranean evolution: The World Asellidae database.

Area of Science:

• Evolutionary biology
• Ecology
• Genomics

Background:

• Studying phenotypic evolution in novel environments like groundwater is crucial but challenging due to resource limitations.
• Interspecific comparative studies on groundwater adaptation are scarce, hindering our understanding of evolutionary processes.

Purpose of the Study:

• To create accessible tools and resources for studying the evolution of freshwater isopods (Asellidae) transitioning to groundwater habitats.
• To facilitate large-scale phylogenetic comparative analyses of surface-to-subterranean transitions.

Main Methods:

• Developed the World Asellidae database (WAD) with species occurrences, specimens, DNA data, and metadata.
• Constructed a large-scale, dated phylogenetic tree for the Asellidae family.
• Identified 34 surface-subterranean species pairs as replicates of groundwater colonization.

Main Results:

• The World Asellidae database (WAD) provides a FAIR resource for thousands of species, specimens, and DNA sequences.
• Phylogenetic reconstruction identified numerous independent transitions from surface to groundwater environments within Asellidae.
• Demonstrated a significant decrease in male body size relative to females in groundwater-colonizing isopods.

Conclusions:

• The WAD and phylogenetic framework offer unprecedented opportunities to study groundwater adaptation in Asellidae.
• Phylogenetically controlled analysis reveals sex-specific body size shifts during groundwater colonization, likely driven by sexual selection.
• These resources and findings pave the way for exploring trait evolution under new environmental pressures.