Spintharus flavidusin the Caribbean—a 30 million year biogeographical history and radiation of a ‘widespread species’

• DOI: 10.7717/peerj.1422
• Publication Date: 2015-11-19T10:01:34Z
• Authors: Austin Dziki; Greta J. Binford; Jonathan A. Coddi...; Ingi Agnarsson
• Keywords: Endemism; Biota; Lineage (genetic)

The Caribbean island biota is characterized by high levels of endemism, the result an interplay between colonization opportunities on islands and effective oceanic barriers among them. A relatively small percentage represented 'widespread species,' presumably taxa for which are ineffective. Few studies have explored in detail genetic structure widespread taxa. cobweb spider Spintharus flavidus Hentz, 1850 (Theridiidae) one two described species unique being widely distributed from northern N. America to Brazil throughout Caribbean. As a taxonomic hypothesis, "flavidus" predicts maintenance gene flow islands, prediction that seems contradicted known S. biology, suggests limited dispersal ability. part extensive survey arachnids (project CarBio), we conducted first molecular phylogenetic analysis with primary goal testing species' hypothesis. Our results, while three loci, reject hypothesis single species. Instead this lineage represent radiation at least 16 region. Nearly all short range endemics several distinct mainland groups others endemics. While taxon sampling, specimen America, constrains what can infer about biogeographical history lineage, clear patterns still emerge. Consistent overwater dispersal, find evidence 30 million years ago, coinciding timing GAARLandia landbridge In sum, not capable frequent but rather my old provides preliminary support complex contested geological