The spatio-temporal colonization and diversification across the Indo-Pacific by a ‘great speciator’ (Aves,Erythropitta erythrogaster)

Abstract

The Indo-Pacific region has arguably been the most important area for the formulation of theories about biogeography and speciation, but modern studies of the tempo, mode and magnitude of diversification across this region are scarce. We study the biogeographic history and characterize levels of diversification in the wide-ranging passerine bird Erythropitta erythrogaster using molecular, phylogeographic and population genetics methods, as well as morphometric and plumage analyses. Our results suggest that E. erythrogaster colonized the Indo-Pacific during the Pleistocene in an eastward direction following a stepping stone pathway, and that sea-level fluctuations during the Pleistocene may have promoted gene flow only locally. A molecular species delimitation test suggests that several allopatric island populations of E. erythrogaster may be regarded as species. Most of these putative new species are further characterized by diagnostic differences in plumage. Our study reconfirms the E. erythrogaster complex as a 'great speciator': it represents a complex of up to 17 allopatrically distributed, reciprocally monophyletic and/or morphologically diagnosable species that originated during the Pleistocene. Our results support the view that observed latitudinal gradients of genetic divergence among avian sister species may have been affected by incomplete knowledge of taxonomic limits in tropical bird species.

Phylogeography of a ‘great speciator’ (Aves:Edolisoma tenuirostre) reveals complex dispersal and diversification dynamics across the Indo‐Pacific

“…The colonization of the North Melanesian and the North Wallacean archipelagos followed stepping‐stone pathways (Figure S2.2a–b in Appendix S2). A similar genetic pattern was found for another ‘great speciator’, the Erythropitta erythrogaster complex, which colonized the Indo‐Pacific in the middle Pleistocene (Irestedt et al., ). However, the biogeographic analyses indicate at least one case of ‘upstream colonization’ by E. tenuirostre of the Australo‐Papuan mainland, probably from the Melanesian Archipelago.…”

“…The E. tenuirostre complex ranges east of Wallace's line into the Near‐Pacific, with migratory and sedentary populations of E. t. tenuirostre occurring almost along the entire Australian north and east coast (Taylor, ; Figure ). Few molecular studies have explored intraspecific patterns of diversification with a dense sampling across the range of a great speciator (but see Garcia‐Ramirez & Trewick, ; Garcia‐Ramirez et al., ; Irestedt et al., ; Jønsson et al., ; Moyle et al., ). In this study, we initially reconstruct phylogenetic relationships and colonization history of the genus Edolisoma and in particular the hyperdiverse E. tenuirostre subspecies complex.…”

Diversification of a ‘great speciator’ in the Wallacea region: differing responses of closely related resident and migratory kingfisher species (Aves: Alcedinidae:Todiramphus)

“…Mayr and Diamond (2001) developed the 'great speciator' concept for their study system in Northern Melanesia to describe a group of birds with high inter-island geographical variation, including diverse taxa found across many islands (e.g. In recent years modern molecular methods have enabled researchers to begin to uncover the intricate evolutionary histories of the 'great speciators', showing them to be complexes of closely related species (Andersen et al 2013, Irestedt et al 2013, Pedersen et al 2018. Because of their wide ranges and multiple distinct populations, the 'great speciators' have provided ideal study systems for developing many key concepts in evolutionary biology (Mayr 1942, Diamond 1974, Diamond et al 1976).…”

Full Issue

“…This lineage may have originated in Wallacea, and eustatic sea-level changes could have aided colonization by reducing overwater dispersal distances. Lowered sea level during glacial phases of the Pleistocene reduced the distance between some land areas, including between Papua New Guinea and Australia (Voris 2000, Hall 2009, Jønsson et al 2010, Wurster et al 2010, Lohman et al 2011, Condamine et al 2013, Irestedt et al 2013). They did not, however, significantly alter the overwater distance between Australia and New Zealand (Graham 2008).…”