The " Atlantis Forest hypothesis " adds a new dimension to Atlantic Forest biogeography (original) (raw)
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Journal of Zoological Systematics and Evolutionary Research, 2013
ABSTRACT We assess whether correlative paleoclimatic models of species ranges accurately predict genetic diversity patterns in species of distinct life histories traits in the Atlantic Forest (AF) of Brazil. To this end, we use sequences of the mitochondrial gene ND2 from Dendropsophus elegans and Chiasmocleis carvalhoi – summarized in the shape of phylogenies and population genetic statistics – and maximum entropy models of species distributions under current, 21 kya BP and 120 kya BP climatic reconstructions. The two target species have distinct ranges, habitat tolerances, rates of reproduction and dispersal abilities, yet are endemic to the AF. Although the more restricted and semi-fossorial C. carvalhoi is associated with forested habitats and thought to be a poor disperser, the widely ranged arboreal D. elegans inhabits open areas such as pastures and human-impacted regions of the AF, and is easily found perched on herbaceous vegetation in inundated areas. We had anticipated that correlative distribution models of the broadly distributed D. elegans would perform better then models of the narrowly ranged C. carvalhoi, thus better predicting current patterns of genetic diversity. The results demonstrate poor predictive ability of climate-based models of C. carvalhoi under current climatic conditions, suggesting that factors such as biotic interactions or dispersal ability may be playing a central role in defining this species distribution – both now and in the recent past. Models under current climate are nonetheless accurate in the broadly ranged D. elegans. As a corollary, paleoclimatic models accurately predicted patterns of diversity of the ND2 mitochondrial gene in D. elegans, but not in C. carvalhoi. We attribute these distinct responses to the poor explanatory power of paleodistributions models when applied to species that violate the basic assumption of the environment as main driver of distribution patterns. This calls for a careful use of distribution models for the purpose of evolutionary biogeographical inference. Like C. carvalhoi, other species whose ranges are not yet at equilibrium, or which are impacted by competitor, parasite or pathogen presence, may not be suitable to the combined use of paleoclimatic-model based phylogeographic inference, as here implemented – despite relatively high area under the curve values.
The phylogenetic position of the enigmatic Atlantic forest
2013
Background: The phylogenetic position of the sigmodontine genus Abrawayaomys, historically assigned to the tribe Thomasomyini or considered a sigmodontine incertae sedis, was assessed on the basis of nuclear and mitochondrial DNA sequences obtained from four individuals from different localities in the Atlantic forest of Brazil. Sequences of Abrawayaomys were analyzed in the context of broad taxonomic matrices by means of maximumlikelihood (ML) and Bayesian analyses (BA). Results: The phylogenetic position of Abrawayaomys differed depending on the gene analyzed and the analysis performed (interphotoreceptor retinoid-binding protein (IRBP) ML: sister to Thomasomyini; IRBP BA: sister to Akodontini; cytochrome (Cyt) b ML: sister to Neotomys; and Cyt b BA: sister to Reithrodontini). With the sole exception of the BA based on Cyt b sequences, where the Abrawayaomys-Reithrodon clade had strong support, all sistergroup relationships involving Abrawayaomys lacked any significant support. Conclusions: As such, Abrawayaomys constitutes the only representative so far known of one of the main lineages of the sigmodontine radiation, differing from all other Atlantic forest sigmodontine rodents by having a unique combination of morphological character states. Therefore, in formal classifications, it should be regarded as a Sigmodontinae incertae sedis.
Journal of Ornithology, 2019
Several evolutionary processes seem to have influenced the Atlantic Forest (AF) biogeographic history, as suggested by phylogeographic studies that have shown a multitude of patterns. Here, we use approximate Bayesian computation to test alternative historical hypotheses to investigate the phylogeographic pattern, historical demography, and palaeodistribution of the Grey-hooded Flycatcher Mionectes rufiventris, an endemic AF bird, distributed mainly in southern areas of the biome. Our goal was to integrate molecular and ecological data to test diversification hypotheses available for the AF. Our investigation revealed two mitochondrial phylogroups, geographically structured around the Doce River. Coalescence analyses revealed that these groups shared a common ancestor in the Late Pleistocene, between 200,000 and 300,000 years ago, and that divergence was probably associated with climatic fluctuations during this period. Demographic analyses suggested recent demographic expansion in both groups. Ecological niche modelling suggested larger ranges during the Last Glacial Maximum (LGM) than in the present, not in agreement with the genetic pattern recovered. We simulated alternative historical models to test these competing scenarios. Our findings support the existence of small populations during the LGM which expanded afterwards from putative refuges. Thus, these results suggest that the Pleistocene climate shaped patterns of diversification and demographic history of this species in accordance with the classical forest refuge hypothesis. Keywords Approximate Bayesian computation • Ecological niche modelling • Forest refuge hypothesis • Mionectes rufiventris • Neotropical region • Statistical phylogeography Zusammenfassung Klimaänderungen im späten Pleistozän prägten die Populationsdivergenz eines Singvogels der Mata Atlantica: ein modellbasierter Test phylogeografischer Hypothesen Mehrere evolutionäre Prozesse scheinen die biogeografische Geschichte der Mata Atlantica (engl.: Atlantic Forest, AF) beeinflusst zu haben, wie phylogeografische Studien nahelegen, welche eine Unzahl von Mustern aufgedeckt haben. Mittels Bayes'scher Näherungsrechnung (engl.: Approximate Bayesian Computation, ABC) prüften wir alternative historische Hypothesen, um die phylogeografischen Muster, die historische Demografie sowie die paläologische Verbreitung des Graukopf-Pipratyrann Mionectes rufiventris zu untersuchen, einer für den AF endemischen Vogelart, welche überwiegend in den südlichen Bereichen dieses Biomes verbreitet ist. Unser Ziel war es, unter Einbeziehung molekularer und ökologischer Daten die für den AF verfügbaren Diversifikationshypothesen zu prüfen. Unsere Multilokus-Untersuchung ließ zwei phylogenetische Gruppen erkennen, die geografisch um den Rio Doce angeordnet waren. Koalenszenzanalysen zeigten, dass diese Gruppen einen gemeinsamen Vorfahren im späten Pleistozän (vor 200.000-300.000 Jahren) besaßen und dass die Communicated by J. T. Lifjeld.
PloS one, 2016
We aim to evaluate the genetic structure of an Atlantic Forest amphibian species, Scinax eurydice, testing the congruence among patterns identified and proposed by the literature for Pleistocene refugia, microrefugia, and geographic barriers to gene flow such as major rivers. Furthermore, we aim to evaluate predictions of such barriers and refugia on the genetic structure of the species, such as presence/absence of dispersal, timing since separation, and population expansions/contractions. We sequenced mitochondrial and nuclear genetic markers on 94 tissue samples from 41 localities. We inferred a gene tree and estimated genetic distances using mtDNA sequences. We then ran population clustering and assignment methods, AMOVA, and estimated migration rates among populations identified through mtDNA and nDNA analyses. We used a dated species tree, skyline plots, and summary statistics to evaluate concordance between population's distributions and geographic barriers and Pleistocene...
Molecular Phylogenetics and Evolution, 2012
In this study we analyzed the phylogeographic pattern and historical demography of an endemic Atlantic forest (AF) bird, Basileuterus leucoblepharus, and test the influence of the last glacial maximum (LGM) on its population effective size using coalescent simulations. We address two main questions: (i) Does B. leucoblepharus present population genetic structure congruent with the patterns observed for other AF organisms? (ii) How did the LGM affect the effective population size of B. leucoblepharus? We sequenced 914 bp of the mitochondrial gene cytochrome b and 512 bp of the nuclear intron 5 of beta-fibrinogen of 62 individuals from 15 localities along the AF. Both molecular markers revealed no genetic structure in B. leucoblepharus. Neutrality tests based on both loci showed significant demographic expansion. The extended Bayesian skyline plot showed that the species seems to have experienced demographic expansion starting around 300,000 years ago, during the late Pleistocene. This date does not coincide with the LGM and the dynamics of population size showed stability during the LGM. To further test the effect of the LGM on this species, we simulated seven demographic scenarios to explore whether populations suffered specific bottlenecks. The scenarios most congruent with our data were population stability during the LGM with bottlenecks older than this period. This is the first example of an AF organism that does not show phylogeographic breaks caused by vicariant events associated to climate change and geotectonic activities in the Quaternary. Differential ecological, environmental tolerances and habitat requirements are possibly influencing the different evolutionary histories of these organisms. Our results show that the history of organism diversification in this megadiverse Neotropical forest is complex.
Journal of Ornithology, 2013
Studies of Atlantic forest (AF) organisms suggest that the historical dynamics of the forest cover produced demographically stable populations in its central region and unstable populations in the southern regions. We studied the mitochondrial phylogeographic structure of an AF passerine, the Greenish Schiffornis Schiffornis virescens (Tityridae), and evaluated questions related to the history of the AF. We analyzed cytochrome b and control region sequences of the mitochondrial genome by traditional phylogenetic and population genetic methods based on summary statistics. In addition, we used coalescent simulations to evaluate specific models of evolution of the populations of S. virescens. The results did not support phylogeographic partitions of the genetic variability of S. virescens. The overall Ust was = 0.32 and gene flow between regions was moderate to high. The analyses suggested that the total population of S. virescens suffered a bottleneck followed by a demographic expansion in the late Pleistocene. The bottleneck might have contributed to the extinction of intraspecific lineages, and hence to the observed lack of a strong phylogeographic pattern and low genetic diversity. Our results suggest that some AF taxa have had all their populations similarly affected by the recent history of the biome, contrary to what has been revealed from most of the other phylogeographic studies in the region and as suggested by a model of AF refuges (the Carnaval-Moritz model). We suggest that the response of organisms to common histories may be idiosyncratic, and predictions about the history of the biome should take into account ecological characteristics and distribution of each specific taxa.
Molecular …, 2011
The increase in biodiversity from high to low latitudes is a widely recognized biogeographical pattern. According to the latitudinal gradient hypothesis (LGH), this pattern was shaped by differential effects of Late Quaternary climatic changes across a latitudinal gradient. Here, we evaluate the effects of climatic changes across a tropical latitudinal gradient and its implications to diversification of an Atlantic Forest (AF) endemic passerine. We studied the intraspecific diversification and historical demography of Sclerurus scansor, based on mitochondrial (ND2, ND3 and cytb) and nuclear (FIB7) gene sequences. Phylogenetic analyses recovered three well-supported clades associated with distinct latitudinal zones. Coalescent-based methods were applied to estimate divergence times and changes in effective population sizes. Estimates of divergence times indicate that intraspecific diversification took place during Middle-Late Pleistocene. Distinct demographic scenarios were identified, with the southern lineage exhibiting a clear signature of demographic expansion, while the central one remained more stable. The northern lineage, contrasting with LGH predictions, exhibited a clear sign of a recent bottleneck. Our results suggest that different AF regions reacted distinctly, even in opposite ways, under the same climatic period, producing simultaneously favourable scenarios for isolation and contact among populations.
Primates, 2011
We have used coalescent analysis of mtDNA cytochrome b (cyt b) sequences to estimate times of divergence of three species of Alouatta-A. caraya, A. belzebul, and A. guariba-which are in close geographic proximity. A. caraya is inferred to have diverged from the A. guariba/A. belzebul clade approximately 3.83 million years ago (MYA), with the later pair diverging approximately 1.55 MYA. These dates are much more recent than previous dates based on molecular-clock methods. In addition, analyses of new sequences from the Atlantic Coastal Forest species A. guariba indicate the presence of two distinct haplogroups corresponding to northern and southern populations with both haplogroups occurring in sympatry within Sao Paulo state. The time of divergence of these two haplogroups is estimated to be 1.2 MYA and so follows quite closely after the divergence of A. guariba and A. belzebul. These more recent dates point to the importance of Pleistocene environmental events as important factors in the diversification of A. belzebul and A. guariba. We discuss the diversification of the three Alouatta species in the context of recent models of climatic change and with regard to recent molecular phylogeographic analyses of other animal groups distributed in Brazil.
Despite the disjunct distribution of Amazonian and Atlantic forests, evidence suggests historical connections. Here we investigated the historical connections between three didelphid mammal species from Amazonian and Atlantic forests (Caluromys philander, Marmosa murina and Marmosa demerarae) to uncover these connections using a comparative phylogeography approach and paleodistribution models. We generated species distribution models from the present and past (Holocene through Pliocene) to evaluate changes in distributions over time focusing on the previously suggested connection regions. We inferred divergence times between populations of each species via the mitochondrial cytochrome b gene, estimated the phylogeographic relationships with haplotype networks, and calculated the genetic distances. All species showed Amazonian and Atlantic Forest divergences between 1 and 2 million years ago, while some populations diverged in more recent times. Paleodistribution was wider for period...