Phylogeographical structure within Boa constrictor imperator across the lowlands and mountains of Central America and Mexico

Abstract

Aim To evaluate the genetic diversity and phylogeographical structure of Boa constrictor imperator, in order to identify the key historical events responsible for its current distribution and diversity. Location The Neotropical region of Mexico and mainland Central America. Methods We used data from the mitochondrial cytochrome b gene, nuclear ornithine decarboxylase intron and microsatellites to perform spatial genetic analyses, and coalescence methods to infer phylogeographical structure, divergence times and historical demography. Results Cytochrome b results revealed two main reciprocally monophyletic lineages, one along the Mexican Pacific coast and another along the Gulf of Mexico, Yucatán Peninsula and Central America, diverging c. 5.2 Ma. Both lineages are subdivided into haplogroups and show steady historical growth and a more recent population expansion. High genetic diversity was observed for both cytochrome b (h = 0.944) and microsatellites (HNei = 0.810–0.900). Main conclusions We demonstrate deep phylogeographical structure with two reciprocally monophyletic lineages and five genetic clusters in Mexico and Central America. Our results suggest that several geographical barriers (including the Trans‐Mexican Volcanic Belt and the Motagua–Polochic–Jocotán faults) and ecological features generated this structure. We report genetic diversity values for the boa at a regional scale and suggest that the two lineages may be considered distinct species.

Phylogeographic structure of Canthon cyanellus (Coleoptera: Scarabaeidae), a Neotropical dung beetle in the Mexican Transition Zone: Insights on its origin and the impacts of Pleistocene climatic fluctuations on population dynamics

“…Therefore, studies comparing more populations are needed to determine whether this species is still cohesive or if it is a complex of cryptic species. Hence, various genetically and geographically differentiated lineages would be expected in this species, as has been found in some phylogeographic studies for other taxa (Breeschoten et al, 2016;Guevara-Chumacero et al, 2010;Leaché et al, 2013;MaldonadoSánchez et al, 2016;Pringle et al, 2012;Suárez-Atilano et al, 2014).…”

“…Forests drifted to the south during the Pleistocene colder periods; then they 16 returned to the North during the warmer periods (Gómez-Pompa, 1973). This process might have promoted vicariant events as has been suggested for other taxa distributed within Mexico (Guevara-Chumacero et al, 2010;Maldonado-Sánchez et al, 2016;Ornelas et al, 2013;Suárez-Atilano et al, 2014). Finally, the discovery of four individuals collected at the gf population that are genetically more related to individuals at the NGM region than to the other gf samples provide evidence of contemporary migration.…”

“…In addition, our results also show that C. cyanellus is a highly polymorphic species, given the large number of single haplotypes per population. Thus, the absence of haplotypes widely distributed across populations and geographical regions may be due to limited historical gene flow and to the fact that the populations current genetic structure has been determined by historical (isolation by distance) and contemporary (e.g., landscapes transformation) processes that restrict gene exchange between populations due to the fragmentation of landscapes as those existing in the In contrast, other studies carried out with other neotropical taxa, observe a more complex phylogeographic structure associated with the main mountain systems of Mexico (Daza et al 2009;Pedraza-Lara et al, 2015, Suárez-Atilano et al, 2014. Implying that the recent phylogeographic structure of those taxa is due to events that occurred during the Pleistocene.…”

Phylogeographic and population genetic analyses reveal multiple species of Boa and independent origins of insular dwarfism

“…Modern Boid snake distributions are the result of numerous vicariance events associated with the fragmentation of Gondwana, and thus these snakes have been cited as a classic example of the role that plate tectonics plays in shaping species distributions (Bauer, 1993; Laurent, 1979; Noonan and Chippindale, 2006a, b; Rage, 1988, 2001). Recent studies have also examined the phylogenetic relationships among certain Boid lineages, and collectively have identified evidence for previously unrecognized diversity (Colston et al, 2013; Hynková et al, 2009; Reynolds et al, 2014; Suárez-Atilano et al, 2014). …”

“…This resulted in the splitting of B. constrictor ( sensu lato ) into two species: B. constrictor from South America and B. imperator from Central and North America. Suárez-Atilano et al (2014) identified two additional distinct clades in Northern-Central America using dense sampling and data from two genes (mitochondrial cytochrome b and nuclear ornithine decarboxylase) and 10 microsatellites. Given these suggestions of unrecognized species within the genus, and the recently variable taxonomy of the group, we refer to all populations in the genus Boa ( B. constrictor , sensu lato ) as the Boa complex hereafter.…”