Phylogeography of the widespread Caribbean spiny orb weaver Gasteracantha cancriformis

PeerJ

article

Lisa Chamberland¹  Fabian C. Salgado-Roa²  Alma Basco³  Amanda Crastz-Flores⁴  Greta J. Binford⁵  Ingi Agnarsson¹ 

[1] Department of Biology, University of Vermont;Biology Program, Faculty of Natural Sciences and Mathematics, Universidad del Rosario;University of Puerto Rico at Rio Piedras;Universidad Metropolitana ,(now Ana G. Mendez University);Department of Biology, Lewis & Clark College;Department of Entomology, National Museum of Natural History, Smithsonian Institution

关键词: Haplotype network;    Gene flow;    Phylogeny;    Color polymorphism;    Morphology;    Intraspecific relationships;    Species delimitation;    Genetic diversity;   

DOI  :  10.7717/peerj.8976

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Background Modern molecular analyses are often inconsistent with pre-cladistic taxonomic hypotheses, frequently indicating higher richness than morphological taxonomy estimates. Among Caribbean spiders, widespread species are relatively few compared to the prevalence of single island endemics. The taxonomic hypothesis Gasteracantha cancriformis circumscribes a species with profuse variation in size, color and body form. Distributed throughout the Neotropics, G. cancriformis is the only morphological species of Gasteracantha in the New World in this globally distributed genus. Methods We inferred phylogenetic relationships across Neotropical populations of Gasteracantha using three target genes. Within the Caribbean, we estimated genetic diversity, population structure, and gene flow among island populations. Results Our findings revealed a single widespread species of Gasteracantha throughout the Caribbean, G. cancriformis, while suggesting two recently divergent mainland populations that may represent separate species, diverging linages, or geographically isolated demes. The concatenated and COI (Cytochrome c oxidase subunit 1) phylogeny supported a Caribbean clade nested within the New World. Genetic variability was high between island populations for our COI dataset; however, gene flow was also high, especially between large, adjacent islands. We found structured genetic and morphological variation within G. cancriformis island populations; however, this variation does not reflect genealogical relationships. Rather, isolation by distance and local morphological adaptation may explain the observed variation.

【 授权许可】

CC BY