From molecular variations to behavioral adaptations: Unveiling adaptive epistasis in primate oxytocin system.

OBJECTIVE: Our primary objective was to investigate the variability of oxytocin (OT) and the GAMEN binding motif within the LNPEP oxytocinase in primates. MATERIALS AND METHODS: We sequenced the LNPEP segment encompassing the GAMEN motif in 34 Platyrrhini species, with 21 of them also sequenced for the OT gene. Our dataset was supplemented with primate sequences of LNPEP, OT, and the oxytocin receptor (OTR) sourced from public databases. Evolutionary analysis and coevolution predictions were made followed by the macroevolution analysis of relevant amino acids associated with phenotypic traits, such as mating systems, parental care, and litter size. To account for phylogenetic structure, we utilized two distinct statistical tests. Additionally, we calculated binding energies focusing on the interaction between Callithtrix jacchus VAMEN and Pro8OT. RESULTS: We identified two novel motifs (AAMEN and VAMEN), challenging the current knowledge of motif conservation in placental mammals. Coevolution analysis demonstrated a correlation between GAMEN, AAMEN, and VAMEN and their corresponding OTs and OTRs. Callithrix jacchus exhibited a higher binding energy between VAMEN and Pro8OT than orthologous molecules found in humans (GAMEN and Leu8OT). DISCUSSION: The coevolution of AAMEN and VAMEN with their corresponding OTs and OTRs suggests a functional relationship that could have contributed to specific reproductive and adaptive behaviors, including paternal care, social monogamy, and twin births, prominent traits in Cebidae species, such as marmosets and tamarins. Our findings underscore the coevolution of taxon-specific amino acids among the three studied molecules, shedding light on the oxytocinergic system as an adaptive epistatic repertoire in primates.

Cranial morphological variation of Ctenomys lami (Rodentia: Ctenomyidae) in a restricted geographical distribution.

The relationship between chromosomal and morphological variation in mammals is poorly understood. We analyzed the cranial size and shape variation in Ctenomys lami concerning to the geographic variation in their chromosome numbers. This subterranean rodent occurs in a narrow range of sand-dunes in the Coastal Plain of southern Brazil. This species presents a high karyotypic variation with diploid numbers varying from 2n = 54 to 2n = 58, involving the fission and fusion of chromosome pairs 1 and 2. Due to different chromosome rearrangement frequencies along their geographic distribution, four karyotypic blocks were proposed. This study, explored cranium shape and size variation in geographical, chromosomal polymorphism, and chromosome rearrangements contexts to test whether the four karyotypic blocks reflect morphologically distinct units. For this, we measured 89 craniums using geometric morphometrics and used uni and multivariate statistics to discriminate the predicted groups and test for an association among chromosomal and morphological variation. Our results show the size and shape of sexual dimorphism, with males larger than females, and support the existence of four karyotypic blocks for Ctenomys lami based on morphological variation. However, our results do not support a direct relationship between chromosomal and cranial morphological variation in C. lami.

Exploring the diversity of AVPR2 in Primates and its evolutionary implications.

The current study focuses on the investigation of AVPR2 (VTR2C) protein-coupled receptor variants specific to different primate taxa. AVPR2 is activated by the neurohormone AVP, which modulates physiological processes, including water homeostasis. Our findings reveal positive selection at three AVPR2 sites at positions 190, 250, and 346. Variation at position 250 is associated with human Congenital Nephrogenic Diabetes Insipidus (cNDI), a condition characterized by excessive water loss. Other 13 functional sites with potential adaptive relevance include positions 185, 202, 204, and 252 associated with cNDI. We identified SH3-binding motifs in AVPR2's ICL3 and N-terminus domains, with some losses observed in clades of Cercopithecidae, Callitrichinae, and Atelidae. SH3-binding motifs are crucial in regulating cellular physiology, indicating that the differences may be adaptive. Co-evolution was found between AVPR2 residues and those in the AVP signal peptide/Neurophysin-2 and AQP2, other molecules in the same signaling cascade. No significant correlation was found between these Primates' taxon-specific variants and the bioclimatic variables of the areas where they live. Distinct co-evolving amino acid sequences in functional sites were found in Platyrrhini and Catarrhini, which may have adaptive implications involving glucocorticoid hormones, suggesting varied selective pressures. Further studies are required to confirm these results.

Evolutionary radiation in canids following continental colonizations.

Colonization of a new environment may trigger an evolutionary radiation, defined as an accelerated accumulation of species in a short period of time. However, how often colonization events trigger such radiations is still an open question. We studied the worldwide dispersal of Caninae to investigate whether the invasion of new continents resulted in elevated species diversification. We used a combination of ancestral range estimation and phylogenetic analyses to estimate the ancestral ranges of 56 extant and extinct species of Caninae, as well as variation in speciation and extinction rates through time and across clades. Our findings indicate that canids experienced an evolutionary radiation event when lineages were able to reach Eurasia and South America around 11 million years ago. A large number of species arising in a short period of time suggests that canids experienced ecological opportunity events within the new areas, implying that the differences in the ecological settings between continents, and size variation among Canidae and other carnivores may be responsible for the variation in clade dynamics. We suggest that the increase of grasslands and the new herbivorous fauna that came with it were the major forces responsible for the diversification of wolves in North America, while empty niches and the absence of competitors can explain the success of canids in Africa and South America. Interaction with other carnivores probably also affected the diversification dynamics of canids.

Bridging macroecology and macroevolution in the radiation of sigmodontine rodents.

Investigations of phenotypic disparity across geography often ignore macroevolutionary processes. As a corollary, the random null expectations to which disparity is compared and interpreted may be unrealistic. We tackle this issue by representing, in geographical space, distinct processes of phenotypic evolution underlying ecological disparity. Under divergent natural selection, assemblages in a given region should have empirical disparity higher than expected under an evolutionarily oriented null model, whereas the opposite may indicate constraints on phenotypic evolution. We gathered phylogenies, biogeographic distributions, and data on the skull morphology of sigmodontine rodents to discover which regions of the Neotropics were more influenced by divergent, neutral, or constrained phenotypic evolution. We found that regions with higher disparity than expected by the evolutionary-oriented null model, in terms of both size and shape, were concentrated in the Atlantic Forest, suggesting a larger role for divergent natural selection there. Phenotypic disparity in the rest of South America, mainly the Amazon basin, northeastern Brazil, and Southern Andes, was constrained-lower than predicted by the evolutionary model. We also demonstrated equivalence between the disparity produced by randomization-based null models and constrained-evolution null models. Therefore, including evolutionary simulations into the null modeling framework used in ecophylogenetics can strengthen inferences on the processes underlying phenotypic evolution.

Evolutionary implications of dental anomalies in bats.

The gain or loss of anatomical features is an important mechanism of morphological evolution and ecological adaptation. Dental anomalies-the loss or gain of teeth-are widespread and a potential source of craniodental specialization among mammals, yet their macroevolutionary patterns have been rarely explored. We present the first phylogenetic comparative study of dental anomalies across the second largest mammal Order, Chiroptera (bats). We conducted an extensive literature review and surveyed a large sample of museum specimens to analyze the types and prevalence of dental anomalies across bats, and performed phylogenetic comparative analyses to investigate the role of phylogenetic history and dietary specialization on incidence of dental anomalies. We found dental anomalies have a significant phylogenetic signal, suggesting they are not simply the result of idiosyncratic mutations or random developmental disorders, but may have ancestral genetic origins or result from shared developmental pathways among closely related species. The incidence of dental anomalies was not associated with diet categories, suggesting no effect of craniodental specialization on dental anomalies across bats. Our results give insight into the macroevolutionary patterns of dental anomalies in bats, and provide a foundation for investigating new hypotheses underlying the evolution of dental variation and diversity in mammals.

Is evolution faster at ecotones? A test using rates and tempo of diet transitions in Neotropical Sigmodontinae (Rodentia, Cricetidae).

We evaluated whether evolution is faster at ecotones as niche shifts may be needed to persist under unstable environment. We mapped diet evolution along the evolutionary history of 350 sigmodontine species. Mapping was used in three new tip-based metrics of trait evolution - Transition Rates, Stasis Time, and Last Transition Time - which were spatialized at the assemblage level (aTR, aST, aTL). Assemblages were obtained by superimposing range maps on points located at core and ecotone of the 93 South American ecoregions. Using Linear Mixed Models, we tested whether ecotones have species with more changes from the ancestral diet (higher aTR), have maintained the current diet for a shorter time (lower aST), and have more recent transitions to the current diet (lower aLT) than cores. We found lower aTR, and higher aST and aLT at ecotones than at cores. Although ecotones are more heterogeneous, both environmentally and in relation to selection pressures they exert on organisms, ecotone species change little from the ancestral diet as generalist habits are necessary toward feeding in ephemeral environments. The need to incorporate phylogenetic uncertainty in tip-based metrics was evident from large uncertainty detected. Our study integrates ecology and evolution by analyzing how fast trait evolution is across space.

Harrison's rule scales up to entire parasite assemblages but is determined by environmental factors.

Harrison's rule states that parasite body size and the body size of their hosts tend to be positively correlated. After it was proposed a century ago, a number of studies have investigated this trend, but the support level has varied greatly between parasite/host associations. Moreover, while the rule has been tested at the individual species level, we still lack knowledge on whether Harrison's rule holds at the scale of parasite and host communities. Here, we mapped flea (parasites) and rodent (hosts) body sizes across Mongolia and asked whether Harrison's rule holds for parasite/host assemblages (i.e. whether a parasite's average body size in a locality is positively correlated with its host's average body size). In addition, we attempted to disentangle complex relationships between flea size, host size and environmental factors by testing alternative hypotheses for the determinants of fleas' body size variation. We gathered occurrence data for fleas and rodents from 2,370 sites across Mongolia, constructed incidence matrices for both taxa and calculated the average body sizes of fleas and their hosts over half-degree cells. Then, we applied a path analysis, accounting for spatial autocorrelation, trying to disentangle the drivers of the correlation between parasite and host body sizes. We found a strong positive correlation between average flea and host size across assemblages. Surprisingly though, we found that environmental factors simultaneously affected the body sizes of both fleas and hosts in the same direction, leading to a most likely deceptive correlation between parasite and host size across assemblages. We suggest that environmental factors may, to a great extent, reflect the environmental conditions inside the hosts' burrows where fleas develop and attain their adult body size, thus influencing their larval growth. Similarly, rodent body size is strongly influenced by air temperature, in the direction predicted by Bergmann's rule. If our findings are valid in other host-parasite associations, this may explain the dissenting results of both support and lack thereof for Harrison's rule.

Ecological specialization and niche overlap of subterranean rodents inferred from DNA metabarcoding diet analysis.

Knowledge of how animal species use food resources available in the environment can increase our understanding of many ecological processes. However, obtaining this information using traditional methods is difficult for species feeding on a large variety of food items in highly diverse environments. We amplified the DNA of plants for 306 scat and 40 soil samples, and applied an environmental DNA metabarcoding approach to investigate food preferences, degree of diet specialization and diet overlap of seven herbivore rodent species of the genus Ctenomys distributed in southern and midwestern Brazil. The metabarcoding approach revealed that these species consume more than 60% of the plant families recovered in soil samples, indicating generalist feeding habits of ctenomyids. The family Poaceae was the most common food resource retrieved in scats of all species as well in soil samples. Niche overlap analysis indicated high overlap in the plant families and molecular operational taxonomic units consumed, mainly among the southern species. Interspecific differences in diet composition were influenced, among other factors, by the availability of resources in the environment. In addition, our results provide support for the hypothesis that the allopatric distributions of ctenomyids allow them to exploit the same range of resources when available, possibly because of the absence of interspecific competition.

Habitat productivity is a poor predictor of body size in rodents.

The "resource availability hypothesis" predicts occurrence of larger rodents in more productive habitats. This prediction was tested in a dataset of 1,301 rodent species. We used adult body mass as a measure of body size and normalized difference vegetation index (NDVI) as a measure of habitat productivity. We utilized a cross-species approach to investigate the association between these variables. This was done at both the order level (Rodentia) and at narrower taxonomic scales. We applied phylogenetic generalized least squares (PGLS) to correct for phylogenetic relationships. The relationship between body mas and NDVI was also investigated across rodent assemblages. We controlled for spatial autocorrelation using generalized least squares (GLS) analysis. The cross-species approach found extremely low support for the resource availability hypothesis. This was reflected by a weak positive association between body mass and NDVI at the order level. We find a positive association in only a minority of rodent subtaxa. The best fit GLS model detected no significant association between body mass and NDVI across assemblages. Thus, our results do not support the view that resource availability plays a major role in explaining geographic variation in rodent body size.

Hybridization between subterranean tuco-tucos (Rodentia, Ctenomyidae) with contrasting phylogenetic positions.

Reproductive compatibility usually decreases according to increasing genetic difference and the time of divergence between species. However, the amount of modification required to influence hybridization may vary in different species. Thus, it is extremely important to conduct studies that seek to understand what and how variables influence the reproductive isolation of species. We have explored a system involving two species of subterranean rodents that present morphological, karyotypic, and evolutionary history differences and are capable of generating hybrids. To gain insight into the karyotype organization of genus Ctenomys, we examined the chromosome evolution by classical and molecular cytogenetics of both parental species and hybrids. Furthermore, we have used different approaches to analyze the differences between the parental species and the hybrids, and determined the origin of the hybrids. The results of our work demonstrate unequivocally that some species that present extensive differences in chromosome organization, phenotype, evolutionary history, sperm morphology and genetic, which are usually associated with reproductive isolation, can generate natural hybrids. The results also demonstrate that females of both species are able to generate hybrids with males of the other species. In addition, the chromosome-specific probes prepared from Ctenomys flamarioni provide an invaluable tool for comparative cytogenetics in closely related species.

Digest: Adaptive radiations and the multidimensional niche.

Adaptive radiations depend critically on ecological opportunity as a driver. Aristide et al. (2018) found that a model incorporating the multivariate niche explains the morphological divergence in New World monkeys better than models with a single ecological axis. This raises the question of whether other continental radiations would show signals of adaptive radiation if the niche is more accurately described.

Divergent genetic mechanism leads to spiny hair in rodents.

Spines, or modified hairs, have evolved multiple times in mammals, particularly in rodents. In this study, we investigated the evolution of spines in six rodent families. We first measured and compared the morphology and physical properties of hairs between paired spiny and non-spiny sister lineages. We found two distinct hair morphologies had evolved repeatedly in spiny rodents: hairs with a grooved cross-section and a second near cylindrical form. Compared to the ancestral elliptical-shaped hairs, spiny hairs had higher tension and stiffness, and overall, hairs with similar morphology had similar functional properties. To examine the genetic basis of this convergent evolution, we tested whether a single amino acid change (V370A) in the Ectodysplasin A receptor (Edar) gene is associated with spiny hair, as this substitution causes thicker and straighter hair in East Asian human populations. We found that most mammals have the common amino acid valine at position 370, but two species, the kangaroo rat (non-spiny) and spiny pocket mouse (spiny), have an isoleucine. Importantly, none of the variants we identified are associated with differences in rodent hair morphology. Thus, the specific Edar mutation associated with variation in human hair does not seem to play a role in modifying hairs in wild rodents, suggesting that different mutations in Edar and/or other genes are responsible for variation in the spiny hair phenotypes we observed within rodents.

Can Niche Modeling and Geometric Morphometrics Document Competitive Exclusion in a Pair of Subterranean Rodents (Genus Ctenomys) with Tiny Parapatric Distributions?

Species with similar ecological requirements coexisting in the same geographic region are prone to competitively exclude each other. Alternatively, they may coexist if character displacement acts to change the niche requirements of one or both species. We used two methodological approaches (ecological niche modeling [ENM] and geometric morphometrics) to test two hypotheses: given their behavioral, morphological, and ecological similarities, one species competitively excludes the other; and, character displacement enables their coexistence at two sites in which the species are known to occur in sympatry. The results from the ENM-based approach did not provide evidence for competitive exclusion; however, the morphometric analyses documented displacement in size of C. minutus. This result, suggests that C. minutus might exclude C. flamarioni from areas with softer soils and higher food availability. We stress the importance of using multiple methodological approaches when testing prediction of competitive exclusion. However, both methods had limited explanatory power given that the focal species possess truly peculiar distributions, being largely parapatric and restricted to narrow, small geographic areas with a strange distribution and there is a need to search for additional methods. We discuss the idiosyncrasy of the ENM-based approach when applied to organisms with subterranean habits.

Pleistocene climatic oscillations in Neotropical open areas: Refuge isolation in the rodent Oxymycterus nasutus endemic to grasslands.

Pleistocene climatic oscillations favoured the expansion of grassland ecosystems and open vegetation landscapes throughout the Neotropics, and influenced the evolutionary history of species adapted to such environments. In this study, we sampled populations of the rodent Oxymycterus nasutus endemic to open areas in the Pampas and Atlantic Forest biomes to assess the tempo and mode of population divergence using an integrative approach, including coalescence theory, ecological niche models, and morphometry. Our results indicated that these O. nasutus populations exhibited high levels of genetic structure. Six major mtDNA clades were found, structuring these biomes into distinct groups. Estimates of their divergence times was indicated to be 0.571 myr. The high degree of genetic structure is reflected in the analyses of geometric morphometric; skull differences between lineages in the two ecoregions were detected. During the last glacial maximum, there was a strong increase in suitable abiotic conditions for O. nasutus. Distinct molecular markers revealed a population expansion over time, with a possible demographic retraction during the post-glacial period. Considering that all clades coalesce with the last interglacial maximum, our results indicated that reduction in suitable conditions during this period may have resulted in a possible vicariance associated with refuge isolation.

The ecology of a continental evolutionary radiation: Is the radiation of sigmodontine rodents adaptive?

Evolutionary radiations on continents are less well-understood and appreciated than those occurring on islands. The extent of ecological influence on species divergence can be evaluated to determine whether a radiation was ultimately the outcome of divergent natural selection or else arose mainly by nonecological divergence. Here, we used phylogenetic comparative methods to test distinct hypotheses corresponding to adaptive and nonadaptive evolutionary scenarios for the morphological evolution of sigmodontine rodents. Results showed that ecological variables (diet and life-mode) explain little of the shape and size variation of sigmodontine skulls and mandibles. A Brownian model with varying rates for insectivory versus all other diets was the most likely evolutionary model. The insectivorous sigmodontines have a faster rate of morphological evolution than mice feeding on other diets, possibly due to stronger selection for features that aid insectivory. We also demonstrate that rapid early-lineage diversification is not accompanied by high morphological divergence among subclades, contrasting with island results. The geographic size of continents permits spatial segregation to a greater extent than on islands, allowing for allopatric distributions and escape from interspecific competition. We suggest that continental radiations of rodents are likely to produce a pattern of high species diversification coupled with a low degree of phenotypic specialization.

Patterns of Species Richness and Turnover for the South American Rodent Fauna.

Understanding the spatial distribution of species sheds light on the group's biogeographical history, offers clues to the drivers of diversity, and helps to guide conservation strategies. Here, we compile geographic range information for South America's diverse rodents, whose 14 families comprise ~50% of the continent's mammalian species. The South American rodent fauna is dominated by independent and temporally staggered radiations of caviomorph and sigmodontine groups. We mapped species richness and turnover of all rodents and the principal clades to identify the main predictors of diversity patterns. Species richness was highest in the Andes, with a secondary hotspot in Atlantic Forest and some regions of considerable richness in Amazonia. Differences in richness were evident between the caviomorphs and sigmodontines, the former showing the greatest richness in tropical forests whereas the latter show-and largely determine-the all-rodent pattern. Elevation was the main predictor of sigmodontine richness, whereas temperature was the principal variable correlated with richness of caviomorphs. Across clades, species turnover was highest along the Andes and was best explained by elevational relief. In South America, the effects of the familiar latitudinal gradient in species richness are mixed with a strong longitudinal effect, triggered by the importance of elevation and the position of the Andes. Both latitudinal and elevational effects help explain the complicated distribution of rodent diversity across the continent. The continent's restricted-range species-those seemingly most vulnerable to localized disturbance-are mostly distributed along the Andes and in Atlantic Forest, with the greatest concentration in Ecuador. Both the Andes and Atlantic Forest are known hotspots for other faunal and floral components. Contrasting patterns of the older caviomorph and younger sigmodontine radiations underscore the interplay of both historical and ecological factors in determining present-day diversity patterns.

Niche suitability affects development: skull asymmetry increases in less suitable areas.

For conservation purposes, it is important to take into account the suitability of a species to particular habitats; this information may predict the long-term survival of a species. In this sense, morphological measures of developmental stress, such as fluctuating asymmetry, can be proxies for an individual's performance in different regions. In this study, we conducted tests to determine whether areas with different levels of suitability for a species (generated by ecological niche models) were congruent with morphological markers that reflect environmental stress and morphological variance. We generated a Maxent niche model and compared the suitability assessments of several areas with the skull morphology data (fluctuating asymmetry and morphological disparity) of populations of the Atlantic forest endemic to Brazil rodent Akodon cursor. Our analyses showed a significant negative relationship between suitability levels and fluctuating asymmetry levels, which indicates that in less suitable areas, the individuals experience numerous disturbances during skull ontogeny. We have not found an association between morphological variance and environmental suitability. As expected, these results suggest that in environments with a lower suitability, developmental stress is increased. Such information is helpful in the understanding of the species evolution and in the selection of priority areas for the conservation of species.

Diversity of small land mammals in a subtropical Atlantic forest in the western region of the state of Santa Catarina, southern Brazil / Diversidade de pequenos mamíferos terrestres em floresta Atlântica subtropical na região oeste do estado de Santa Catarina, sul do Brasil

Small land mammals possess features that significantly influence the dynamics of ecosystems and participate in various levels of the food web. In the Brazilian Atlantic Forest the richness of these animals is high, which makes them even more ecologically and numerically relevant in this environment. In this context, we investigated the species composition of small mammals in an unexplored area of southern Brazil, and compared the species composition of this area with other Atlantic Forest regions in order to understand how this community is related to others. The study area was located in an interior Atlantic forest formation, at a transition region between deciduous and Araucaria forests. Small mammals were captured at five collection points using pitfall traps. We compared the species composition found in our studied area with the composition of other 11 studies in different regions by a cluster analysis, and we investigated the presence of spatial autocorrelation between communities with a Mantel test. We recorded 779 individuals from 21 species of small rodents (15 species) and marsupials (six species) during the 13 months of the collection period. This richness was high compared to other studies conducted in the Atlantic Forest formations near to coastline and in interior forest formations. This may be a result of the conditions provided by this transition area (deciduous and Araucaria forests), where could be found elements of the both forests formations, which probably allows the establishment of small mammal species from both forest types. Despite differences in sampling effort of the studies, our results suggest that the interior forest formations may harbor a number of species comparable to the formations near the coast. The species composition of this area was similar to those found in other interior forest formations with the same phytophysiognomy characteristics and at nearby regions, and it was less similar to the distant formations located in southeastern and northeastern Brazil and nearby to the coastline. This can be a result of both the spatial autocorrelation (i.e. more nearby communities tend to have more similar species composition) and the differences of forest characteristics among regions.

Pequenos mamíferos terrestres possuem características que influenciam significativamente a dinâmica dos ecossistemas, participando em vários níveis da teia trófica. Na floresta Atlântica brasileira a riqueza desses animais é alta, o que os torna ainda mais ecológica e numericamente relevantes neste ambiente. Neste contexto, nós investigamos a composição de espécies de pequenos mamíferos em uma área não estudada, e comparamos a composição de espécies desta área com outras regiões de floresta Atlântica de modo a entender como esta comunidade de pequenos mamíferos é relacionada a outras. A área de estudo está localizada em uma formação de floresta Atlântica de interior, em uma transição entre floresta decidual e floresta com Araucária. Os pequenos mamíferos foram capturados em cinco pontos de coleta por meio do método de armadilhas de interceptação e queda. Nós comparamos a composição de espécies encontrada em nosso estudo com a de outros 11 estudos realizados em diferentes regiões através de uma análise de agrupamento, e nós investigamos a presença de autocorrelação espacial entre comunidades por meio de um teste de Mantel. Nós registramos 779 indivíduos de 21 espécies de pequenos roedores (15 espécies) e marsupiais (seis espécies) durante um período de 13 meses de coleta. A riqueza é alta comparada com outros estudos em formações de floresta Atlântica próximas do litoral e formações de interior. Isso pode ser o resultado das condições fornecidas por esta área de transição (floresta decidual e floresta com Araucária), onde podem ser encontrados elementos das duas formações florestais, o que provavelmente permite o estabelecimento de espécies de pequenos mamíferos dos dois tipos de floresta. Apesar das diferenças no esforço amostral entre os estudos, esses resultados são uma boa indicação de que as formações de floresta Atlântica de interior podem abrigar um número de espécies comparáveis a de formações próximas da costa. A composição de espécies desta área é mais similar a de outras formações Atlânticas de interior com as mesmas características florestais e de regiões espacialmente próximas, e é menos similar as formações localizadas no sudeste e no nordeste do Brasil, e de regiões próximas da costa. Isso pode ser o resultado de autocorrelação espacial (i.e. comunidades mais próximas tendem a ter uma composição de espécies mais similar) e das diferenças nas características florestais entre as regiões.