Supplementary Text
We searched the Web of Science database using the following keywords:
Geographic barriers : Daphnia + allopatric; Daphnia + geography; Daphnia + geographic; Daphnia + phylogeography; Daphnia + biogeography/biogeographic; Daphnia + vicariance/vicariant; Daphnia + endemism; Daphnia + divergence; Daphnia + refugia
Ecological barriers : Daphnia + temporal isolation; Daphnia + allochronic; Daphnia + temporal; Daphnia + photoperiod; Daphnia + diapause; Daphnia + habitat isolation; Daphnia + ecological isolation; Daphnia + habitat; Daphnia + ecology
Non-ecological barriers : Daphnia + mating; Daphnia + mate; Daphnia + mate choice; Daphnia + sperm; Daphnia + testes
Postzygotic barriers: Daphnia + postzygotic isolation; Daphnia + postzygotic; Daphnia + hybrid vigor; Daphnia + heterosis; Daphnia + hybrid inviability; Daphnia + inviability; Daphnia + sterility; Daphnia + hybrid
Supplementary Table 1. Summary of Daphnia speciation studies that examines ecological, non-ecological, geographic barriers, and hybridization. Each study is listed by the type of isolating mechanism and barrier (if not applicable, ‘NA’ is listed), as well as the evidence and protocol used to detect the isolating mechanism for each pair of species in the subgenus/species complex.