Phylogeography of the widespread spider Nephila clavipes (Araneae: Araneidae) in South America indicates geologically and climatically driven lineage diversification

Abstract

Aim Amazonia and Atlantic Rain Forests share a common biogeographical origin and have an interconnected history that includes the drier biomes between them. It is not clear if the establishment of the South American Dry Diagonal promoted isolation between these forests or if connections between them have occurred after this event. We sought to investigate biotic diversification and geographical evolution in these biomes with a phylogeographical study of Nephila clavipes, a rain forest dwelling spider. Location South America. Methods We collected 320 individuals from 49 sites and sequenced one mitochondrial and two nuclear DNA regions. We analysed the genetic diversity, structure and demography, did phylogenetic inferences, estimated divergence times, inferred ancestral areas and applied a model‐based approach to test competitive hypotheses on the species’ evolution. Results An ancient split, coincident with the Central Cordillera final uplift, segregated a Trans‐Andean Colombian lineage from the others. Four lineages occur in Brazil, with a Pleistocene divergence: one in Amazonia, one in the northern and southern Atlantic Forest and two associated with the Dry Diagonal, but also reaching the Southern Atlantic Forest and Amazonia. The biogeographical analysis indicated that some lineages have expanded their ranges along the Pleistocene. Main conclusions Pleistocene connections of Amazonia and Atlantic rain forests through the central part of the Cerrado were supported. No phylogeographical break was detected along the Atlantic Forest. Geological and climatic events contributed to lineage diversification in N. clavipes. Studying widely distributed species is primary in unveiling evolutionary patterns in highly complex regions.

Caribbean golden orbweaving spiders maintain gene flow with North America

“…More precisely, some GMYC, mPTP and some ABGD suggest more than two species over the entire T. clavipes range. While T. clavipes may in fact contain more than a single, Panamerican species, consistent with a population genetic study in South America (Bartoleti, Peres, Fontes, da Silva, & Solferini, 2018), this result contradicts the classical morphological taxonomy (Kuntner, 2017).…”

“…We emphasized the richness in geographic terminal coverage over that of using more genes with fewer terminals. Using COI to resolve phylogeographic questions is a common and valid approach (Bartoleti et al, ; Čandek & Kuntner, ; Su et al, ).…”

“…Area COI-GenBank COI-BOLD fewer terminals. Using COI to resolve phylogeographic questions is a common and valid approach (Bartoleti et al, 2018;Čandek & Kuntner, 2015;Su et al, 2006).…”

Caribbean golden orbweaving spiders maintain gene flow with North America

“…However, these alternatives are less credible because they also suggest unrealistic species lumps of morphologically welldiagnosed species on other continents, such as T. komaci and T. sumptuosa being detected as a single species. Our conclusion that T. clavipes may in fact contain more than a single, Panamerican species, contradicts the classical morphological taxonomy (Kuntner 2017) but is consistent with a population genetic study in South America (Bartoleti et al 2018).…”

“…Our total dataset contains every available T. clavipes cytochrome c oxidase subunit 1 (COI) sequence from the combined Caribbean + USA region (N = 58), an equal number of COI sequences randomly selected from Brazilian T. clavipes (Bartoleti et al 2018), and every available sequence of T. clavipes from other areas (4 x Panama, 4 x Colombia, 1 x French Guiana, 1 x Costa Rica, 1 x Mexico). We also targeted other Trichonephila global exemplars (1 to 6 terminals per species, 8 species total), and four individuals of Nephila pilipes as the outgroup (Supplementary table S1).…”