Stability Predicts Genetic Diversity in the Brazilian Atlantic Forest Hotspot

Abstract

Biodiversity hotspots, representing regions with high species endemism and conservation threat, have been mapped globally. Yet, biodiversity distribution data from within hotspots are too sparse for effective conservation in the face of rapid environmental change. Using frogs as indicators, ecological niche models under paleoclimates, and simultaneous Bayesian analyses of multispecies molecular data, we compare alternative hypotheses of assemblage-scale response to late Quaternary climate change. This reveals a hotspot within the Brazilian Atlantic forest hotspot. We show that the southern Atlantic forest was climatically unstable relative to the central region, which served as a large climatic refugium for neotropical species in the late Pleistocene. This sets new priorities for conservation in Brazil and establishes a validated approach to biodiversity prediction in other understudied, species-rich regions.

Conservation genetics of bees: advances in the application of molecular tools to guide bee pollinator conservation

“…Specifically, they analyze variability of mitochondrial genes in the neotropical orchid bee Euglossa iopoecila and find greater genetic diversity in central regions of the Atlantic forest (Brazil), where there was likely greater past climate stability, than in the southern regions, which exhibit signatures of recent population expansion. These results are consistent with the historical biogeography of other forest specialists in this ecoregion (Carnaval et al 2009). In addition to exploring environmental drivers of phylogeographic structure using mitochondrial (COI) microsatellites, Duennes et al (2017) add a morphometric analysis to their study of the Mesoamerican bumblebee B. ephippiatus.…”

MTML-msBayes: Approximate Bayesian comparative phylogeographic inference from multiple taxa and multiple loci with rate heterogeneity

“…Specifically we treat models of isolation and migration as a set of models specified by a categorical model indicator parameter that can be estimated via ABC. In this case the acceptance rejection step can be followed by a polychotomous regression step that has been shown to improve estimation of discrete categorical parameters [15,22,25,32]. To test the accuracy of this technique, the five taxon-pair data was simulated using 3,000,000 random draws from the hyper-prior with the three different migration models simulating the data with equal probability (one isolation model and two migration models).…”

“…Uncertainty in mutation rate heterogeneity across loci is also accounted for. For example, this software will allow testing for simultaneous divergence [11] and choosing among alternate multi-taxon scenarios such as isolation and migration that can be generated via ecological niche models [15]. Some recent packages have recently made ABC methods accessible to empiricists conducting phylogeographic inference [16-21], and MTML-msBayes complements these by using HABC for comparative phylogeographic datasets.…”

The emerging field of geogenomics: Constraining geological problems with genetic data

“…At present, few species have been sufficiently sampled or studied to approach these questions, but there are examples of forest taxa (Carnaval et al, 2009;d'Horta et al, 2011;Ribas et al, 2012;d'Horta et al, 2013;Jones et al, 2013) that show signs of recent population expansion in Amazonia, Central America, and the southern Atlantic forest, but population retraction in the northern Atlantic forest (d 'Horta et al, 2011). Also, currently isolated populations that occur in open areas within or around Amazonia seem to have been more connected during the Late Pleistocene (Wuster et al, 2005;Bonvicino et al, 2009;VargasRamírez et al, 2010;Capurucho et al, 2013).…”