Biology subjects

Borges, L. M.

Publications and source records attributed to Borges, L. M..

4 recordsLinked to original sources

bioRxiv2025

Morphological innovation and lineage-specific history drive disparification in the aggregated pollen of mimosoid plants

Background and AimsThe study of morphological diversity (i.e., disparity) offers unique opportunities to understand evolutionary patterns and processes. Plant disparity studies reveal that morphological disparification can be related to factors such as secondary woodiness or to pollination niche, for example. Similarly, some pollen traits are known to be shaped by environmental pressures, but this influence has only been evaluated in monads, never in multi-grained dispersal units. In this study, we investigated the disparity of aggregated dispersal units in two lineages of Neotropical mimosoid legumes. The Mimosa and Stryphnodendron clades are independent lineages that share similarities in pollen morphology and biome shifts. In this context, we asked: What are the patterns of pollen disparity in these lineages, and are these patterns similar between lineages occurring in the same biomes? MethodsTo answer these questions, we compiled data from the literature on pollen morphology and biomes of occurrence for a phylogenetically representative set of taxa in the Mimosa and Stryphnodendron clades. With these data, we calculated morphospaces and disparity metrics, and tested whether the pollen morphology of distinct lineages occurring in the same biome differs significantly. Key ResultsOur results show that Mimosa and Stryphnodendron clades exhibit distinct patterns of pollen disparity, as do independent lineages occurring in the same biomes. Additionally, we observed that certain biomes support greater or lesser levels of morphological disparity. ConclusionsWe conclude that (1) the Mimosa clade has greater disparity, possibly due to evolution of novel pollen morphologies in the genus Mimosa, (2) there is a maintenance of similarities in the pollen of the Stryphnodendron clade, Adenopodia and Piptadenia, and (3) the evolution of pollen grains in these groups appears to be primarily shaped by phylogeny and developmental constraints, with environmental pressures playing a comparatively smaller role.

plant biology↗

bioRxiv2023

Phylogenetic diversity and regionalization of root nodule symbiosis

AimHere we determine centers of species richness (SR), relative phylogenetic diversity (RPD) and centers of paleo- and neo-endemism, and regionalizations of phylogenetic diversity in the mimosoid clade of the legumes to understand the distribution and environmental associates of mimosoids lacking RNS (root nodule symbiosis). LocationGlobal. Time periodPresent. Major taxa studiedMimosoid legumes. MethodsWe built a phylogenetic tree of 1313 species and high-quality species distribution models for 1128 species representing the phylogenetic breadth of the mimosoid clade to identify the geographic distribution of RNS. Centers of significant RPD and endemism were identified using a randomization approach, the latter using CANAPE. Phylogenetic regionalization used a distance-based phylogenetic beta-diversity approach. ResultsWe recognized nine areas of contiguous high SR as distinct SR hotspots. Non-RNS species occur mainly outside hotspots but are closely correlated with high RPD. Absence of RNS was best predicted by high precipitation, and represents multiple independent phylogenetic assemblages in different biogeographic areas. Main conclusionsSR hotspots are partly incongruent with centers of RPD and phylogenetic endemism. Lineages lacking RNS are distributed in SR hotspots in Africa and the Americas, belong to biogeographically separate species assemblages, and are, in most cases, associated with relatively moist tropical environments with low temperature seasonality and high available soil nitrogen.

ecology↗

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↗

bioRxiv2020

Schrodinger's phenotypes: images of herbarium specimens are both good and (not so) bad sources of morphological data

Museum specimens are the main source of information on organisms’ morphological features. Although access to this information was commonly limited to researchers able to visit collections, it is now becoming freely available thanks to the digitization of museum specimens. With these images, we will be able to collectively build large-scale morphological datasets, but these will only be useful if the limits to this approach are well-known. To establish these limits, we used two-dimensional images of plant specimens to test the precision and accuracy of image-based data and analyses.To test measurement precision and accuracy, we compared leaf measurements taken from specimens and images of the same specimens. Then we used legacy morphometric datasets to establish differences in the quality of datasets and multivariate analyses between specimens and images. To do so, we compared the multivariate space based on original legacy data to spaces built with datasets simulating image-based data.We found that trait measurements made from images are as precise as those obtained directly from specimens, but as traits diminish in size, the accuracy drops as well. This decrease in accuracy, however, has a very low impact on dataset and analysis quality. The main problem with image-based datasets comes from missing observations due to image resolution or organ overlapping. Missing data lowers the accuracy of datasets and multivariate analyses. Although the effect is not strong, this decrease in accuracy suggests caution is needed when designing morphological research that will rely on digitized specimens.As highlighted by images of plant specimens, 2D images are reliable measurement sources, even though resolution issues lower accuracy for small traits. At the same time, the impossibility of observing particular traits affects the quality of image-based datasets and, thus, of derived analyses. Despite these issues, gathering phenotypic data from two-dimensional images is valid and may support large-scale studies on the morphology and evolution of a wide diversity of organisms.Competing Interest StatementThe authors have declared no competing interest.View Full Text

ecology↗