Biology subjects

Barros-Souza, Y.

Publications and source records attributed to Barros-Souza, Y..

3 recordsLinked to original sources

bioRxiv2026

Beyond the Highlands: Climate Drives Evolutionary Connections Between Ancient Neotropical Mountains and Lowland Biomes

AimThe assembly of montane plant communities through time is underlain by historical and abiotic factors. However, the extent of evolutionary connectivity between ancient highland ecosystems and surrounding lowlands remains unclear. Here, we investigate the evolutionary connections between the campos rupestres, a hyperdiverse and fragmented montane vegetation complex in eastern South America, and lowland biomes surrounding it: savannas, rainforests, and seasonally dry tropical forests. LocationEastern South America. Time periodCenozoic. Major taxa studiedFlowering plants. MethodsUsing phylogenetic beta diversity analyses for 13 angiosperm clades, we assess the degree of lineage dissimilarity between campos rupestres subregions and adjacent biomes. We also apply generalized dissimilarity modeling to determine the role of climate, soil, and geographic distance in shaping spatial patterns of phylogenetic composition. ResultsOur results reveal high lineage permeability between campos rupestres and surrounding biomes, with lineage sharing largely reflecting biome adjacency. This pattern is mainly driven by shared climatic conditions, which are the strongest predictors of phylogenetic dissimilarity. Main conclusionsWe highlight the importance of lineage exchange between lowland and montane environments for the assembly of highland floras. By showing that lineage movements across biome boundaries have been common over time and spatial scales, our study challenges the idea that ancient Neotropical mountains are isolated sky-islands. Instead, we emphasize the dynamic nature of montane plant diversity and the pivotal role of climate in shaping evolutionary connections between highlands and lowlands.

plant biology↗

bioRxiv2025

When morphology stands still: constrained floral evolution in a mega diverse legume genus

O_LIChanges in floral morphology are key for the evolutionary success of flowering plants. However, many species-rich and ecologically diverse groups show low variation in floral traits. Low morphological variation may be associated with selective pressures and constraints to changes. Nonetheless, because our understanding of floral morphological evolution is focused on plant groups with diverse and specialized floral morphology, there has been little progress in identifying factors underlying floral morphological uniformity. C_LIO_LIHerein we addressed this issue by asking whether the morphology of flowers in the mega-diverse legume genus Mimosa is shaped by constraints. By investigating patterns and processes underlying trait variation along floral whorls, we evaluated the role of development and/or function in limiting morphological change. C_LIO_LIOur results showed that floral morphology is remarkably homogeneous and likely shaped by convergent evolution. Morphological variation is unevenly distributed across floral whorls, reflecting differences in the levels of constraints. C_LIO_LIFloral morphology in Mimosa is unlikely to have been primarily driven by pollinator-mediated selection. Instead, we suggest that the development and function of flowers in the mimosoid inflorescence constrained morphological evolution in this megadiverse yet morphologically uniform group. C_LI

evolutionary biology↗

bioRxiv2022

No one-size-fits-all: Both general and particular processes shaped the mega-diverse flora of Eastern South American mountains

AimThe astonishing diversity of ancient mountains was likely shaped by multiple evolutionary processes. However, there is an ongoing debate on what were the main processes driving the assembly of campos rupestres, the mega-diverse flora of Eastern South American mountains. Although the ancient nature of these mountains suggests their flora should be composed by relatively older lineages, they harbour a number of recently diverged clades. To better understand the evolution of ancient mountains floras, we tested if the campos rupestres are mainly composed by relatively old or recent communities and if angiosperm diversity is geographically structured using analyses of diversity and endemism. LocationEastern South America. Time periodOligocene/Miocene to the present. Major taxa studiedFlowering plants. MethodsWe used analyses of diversity and endemism for 10% of the campos rupestres flora. We obtained distribution data from online databases, and phylogenetic hypotheses from the literature. With these datasets, we estimated alpha and beta metrics of taxonomic and phylogenetic diversity, and conducted categorical analyses of neo- and paleo-endemism. ResultsPhylogenetic overdispersion predominates in the campos rupestres. However, this general pattern is permeated by both lineage- and site-specific phylogenetic clustering, suggesting that recent diversification events depend on particular regional conditions and on the overall maintenance of old lineages. Although endemism patterns vary among different campos rupestres sites, paleo-endemism is widespread and particularly prominent where phylogenetic overdispersion is evident. Moreover, phylogenetic composition indicates variable past spatial connections across different sites, taxonomic composition is highly geographically structured and seems to be influenced by the vegetation surrounding the campos rupestres and/or by abiotic conditions. Main conclusionsOur results reinforce the idiosyncratic nature of diversification patterns in ancient mountains and suggest that old, climatically buffered, infertile montane ecosystems not only include both relatively old and recent lineages, but that recent diversification is lineage and spatially dependent.

plant biology↗