The Central American land bridge as an engine of diversification in New World doves

Abstract

Aim The closure of the Central American land‐bridge connection between North and South America 3.5 million years ago was a major biogeographic event that allowed considerable interchange of the previously isolated faunas of these continents. However, the role that this connection may have had in diversification of North and South American faunas is less well understood. The goal of this study was to evaluate the potential role of the formation of this land connection in generating diversity, through repeated rare dispersal events followed by isolation. Location North and South America. Methods We evaluated the role of the Central American land‐bridge connection in avian diversification using a molecular phylogeny based on four gene regions for mid‐sized New World doves. Diversification events were dated using a Bayesian relaxed clock analysis and internal calibration points for endemic island taxa with known island ages. Results The reconstructed phylogenetic tree was well supported and recovered monophyly of the genera Leptotila and Zenaida, but the quail‐doves (Geotrygon) were paraphyletic, falling into three separate lineages. The phylogeny indicated at least nine dispersal‐driven divergence events between North and South America. There were also five dispersal events in the recent past that have not yet led to differentiation of taxa (polymorphic taxa). Main conclusions Most of these dispersal‐driven diversification events occurred at the time of or after the formation of the Central American land bridge, indicating that this land connection played a role in facilitating divergence via dispersal of doves between continents.

Phylogenetic analysis of symbionts in feather-feeding lice of the genus Columbicola: evidence for repeated symbiont replacements

“…Previous studies suggested that Columbicola feather lice diversified mainly in the Paleogene [28,29]. Thus, if replacements have occurred, they must have occurred since this time.…”

Molecular systematics of the new world screech-owls (Megascops: Aves, Strigidae): biogeographic and taxonomic implications

“…473 Closure of the Panama isthmus has been estimated at 3.5 mya 474 (Coates and Obando, 1996), but it has recently been suggested that 475 some dispersal across the closing isthmus was possible from 12 to 476 20 mya onwards (Farris et al, 2011). Thus, many avian taxa with 477 CA colonization events, such as the core tanagers (Sedano and 478 Burns, 2009), doves (Johnson and Weckstein, 2011), even theoret-479 ically low-dispersal species such as Sclerurus (d' Horta et al, 2013), 480 and Megascops all took place before the final closure of the isthmus. 481 The reconstruction suggesting that the Amazon forest species Andes.…”

Full Issue

“…In this biogeographic scenario, methods such as dispersal-vicariance analysis (DIVA) that assume vicariance as the null model are inappropriate. Such models are biased toward vicariance events, and could therefore incorrectly attribute a speciation event to vicariance rather than to dispersal (see Weckstein 2011 andBess et al 2014 for further rationale). In this case, North America and South America came into contact, rather than separating from each other, so scenarios that posit vicariance are not biogeographically plausible.…”

“…Due to their ability to fly, avian dispersal between continents was sometimes suggested to be uninhibited by the water barrier that existed prior to land bridge formation (Voelker 1999, Lomolino et al 2006, and the sparse avian fossil record has made it difficult to prove otherwise (Vuilleumier 1985). However, several historical biogeographic reconstructions of Neotropical and Nearctic bird species based on molecular data have indicated that many species were hindered from dispersing between continents due to the water barrier ( Barker 2007, Burns and Racicot 2009, Sedano and Burns 2010, Johnson and Weckstein 2011, Pulgarin-R et al 2013. Instead, the timing of dispersal events appears similar to that of mammals, soon after land bridge formation (Smith and Klicka 2010).…”