Conflict between Genetic and Phenotypic Differentiation: The Evolutionary History of a ‘Lost and Rediscovered’ Shorebird

Abstract

Understanding and resolving conflicts between phenotypic and genetic differentiation is central to evolutionary research. While phenotypically monomorphic species may exhibit deep genetic divergences, some morphologically distinct taxa lack notable genetic differentiation. Here we conduct a molecular investigation of an enigmatic shorebird with a convoluted taxonomic history, the White-faced Plover (Charadrius alexandrinus dealbatus), widely regarded as a subspecies of the Kentish Plover (C. alexandrinus). Described as distinct in 1863, its name was consistently misapplied in subsequent decades until taxonomic clarification ensued in 2008. Using a recently proposed test of species delimitation, we reconfirm the phenotypic distinctness of dealbatus. We then compare three mitochondrial and seven nuclear DNA markers among 278 samples of dealbatus and alexandrinus from across their breeding range and four other closely related plovers. We fail to find any population genetic differentiation between dealbatus and alexandrinus, whereas the other species are deeply diverged at the study loci. Kentish Plovers join a small but growing list of species for which low levels of genetic differentiation are accompanied by the presence of strong phenotypic divergence, suggesting that diagnostic phenotypic characters may be encoded by few genes that are difficult to detect. Alternatively, gene expression differences may be crucial in producing different phenotypes whereas neutral differentiation may be lagging behind.

Local Environment but Not Genetic Differentiation Influences Biparental Care in Ten Plover Populations

“…Phenotypic plasticity, in turn, may be a key facilitator of the unusually wide ecological and geographic range of breeding plovers, and of associated adaptations to the local environments. The latter results are consistent with recent works that show large gene exchange between geographically different plover populations [48], [49], [55], and thus emphasize the significance of phenotypic responses to local environment.…”

“…(i) Within species gene flow may be high between geographically distinct populations, and strong mixing occurs between distant plover populations over large geographic distances [48], [49], [55]. Therefore genetic differences between populations may not be large enough to have a detectable effect on incubation behaviour.…”

North or south? Phylogenetic and biogeographic origins of a globally distributed avian clade

“…For DNA samples extracted from toe pads, primers targeting at least one shorter region per gene were used to handle degradation (Table S3, Supplementary material). For the mtDNA genes ND3 and COI, suitable primers were already available Rheindt et al, 2011), including a set of three primer pairs designed to amplify the COI gene partially D L and Q fragments; Table S3, Supplementary material). For nuclear genes, we designed new primers using Primer3 (Rozen and Skaletsky, 2000).…”

Study on Phylogenetic Status of Javan Plover Bird (Charadrius, Charadriidae, Charadriiformes) through DNA Barcoding Analysis

“…alexandrinus closer to C. leschenaultii than with other species and is supported by bootstrap values of 99% in NJ and 96% in MP. C. melodus closer to C. semipalmatus supported by 99% bootstrap values in NJ and 96% in MP, and similar with Barth et al (2013), Dos Remedios et al (2015, Rheindt et al (2011). Both species are closer to C. dubius but only supported by 58% bootstrap values in NJ and 56% in MP.…”