Tracing the origins of widespread highland species: a case of Neogene diversification across the Mexican sierras in an endemic lizard

Abstract

The evolutionary history of the Mexican sierras has been shaped by various geological and climatic events over the past several million years. The relative impacts of these historical events on diversification in highland taxa, however, remain largely uncertain owing to a paucity of studies on broadly-distributed montane species. We investigated the origins of genetic diversification in widely-distributed endemic alligator lizards in the genus Barisia to help develop a better understanding of the complex processes structuring biological diversity in the Mexican highlands. We estimated lineage divergence dates and the diversification rate from mitochondrial DNA sequences, and combined divergence dates with reconstructions of ancestral geographical ranges to track lineage diversification across geography through time. Based on our results, we inferred ten geographically structured, well supported mitochondrial lineages within Barisia. Diversification of a widely-distributed ancestor appears tied to the formation of the Trans-Mexican Volcanic Belt across central Mexico during the Miocene and Pliocene. The formation of filter barriers such as major river drainages may have later subdivided lineages. The results of the present study provide additional support for the increasing number of studies that suggest Neogene events heavily impacted genetic diversification in widespread montane taxa.

Ecological Speciation in Nolina parviflora (Asparagaceae): Lacking Spatial Connectivity along of the Trans-Mexican Volcanic Belt

“…Instead, our results are more similar to those reported by Bryson & Riddle [27], where tropical montane specialists persisted in isolation over longer periods of time, corroborated by empirical studies of vegetation change in central and western Mexico over the last 86,000 years [51], [52]. Our previous study [22] revealed relatively old divergence times between the eastern and western clades (see their Fig.…”

Molecular phylogenetics and species delimitation of leaf-toed geckos (Phyllodactylidae: Phyllodactylus) throughout the Mexican tropical dry forest

“…Devitt, 2006;Morrone, 2006;Mulcahy and Mendelson III, 2000;Zarza et al, 2008) and also appears to drive cladogenesis within montane species (e.g. Bryson and Riddle, 2012;Bryson et al, 2011a,b;Bryson et al, 2012a,b). The MVB formed in a west-to-east progression beginning at around 23 Ma and ending approximately 2.5 Ma (Moran-Zenteno, 1994).…”

Parametric and non-parametric species delimitation methods result in the recognition of two new Neotropical woody bamboo species

“…1). 663 Speciation along the Trans-Mexican Volcanic Belt is mainly due 664 to the uplift of this mountain range and is related to habitat frag-665 mentation and the resulting isolation of animal and plant popula-666 tions (Bryson et al, 2011a,b;Bryson and Riddle, 2012;Ruiz-667 Sanchez and Specht, 2014). Uplift could be responsible for the iso-668 lation and speciation of both O. victoriae and also that of O.…”