Biology subjects

Maurin, O.

Publications and source records attributed to Maurin, O..

15 recordsLinked to original sources

bioRxiv2025

Trait-dependent diversification and spatio-ecological limits drive angiosperm diversity unevenness across the Canary Islands archipelago

Island biotas often show highly uneven species richness among lineages, influenced by clade age, diversification rates, and/or spatio-ecological limits. However, disentangling these drivers has been challenging due to the lack of comprehensive datasets across multiple lineages in the same geographical arena. The flora of the Canary Islands includes hundreds of plant lineages with contrasting species richness and harbours the highest number of species that evolved their woodiness in-situ ("insular woodiness"). Here, we present a phylogenomic reconstruction for Canary Island angiosperms and show that diversity unevenness in the flora is not driven by lineage age but by trait-dependent diversification and spatio-ecological limits. Our phylogenomic dataset, based on 1,244 newly generated and 501 published DNA sequences for 669 Canary Island species and 771 closely related mainland taxa, allows us to simultaneously study 435 plant lineages ([~]50% of total). Applying dynamic stochastic modelling, we find the flora is shaped by high extinction and colonisation rates, maintaining a macroevolutionary equilibrium. Additionally, insular woody lineages exhibit higher diversification rates than the remaining flora. Our results suggest the uneven diversity of a highly dynamic insular region can be explained by the interaction of trait evolution and ecological constraints, providing insights into island biodiversity dynamics.

evolutionary biology↗

bioRxiv2025

Classification of Urticaceae based on morphology and phylogenetic inference

The Urticaceae (ca. 2600 species) were first formally recognized by Jussieu in the 18th century and last comprehensively monographed by Weddell in the 19th century. Since Weddells work, family delimitation has been modified and many genera described in a fragmented manner. Over the past two decades, numerous molecular studies have supported the inclusion of Cecropiaceae within Urticaceae and identified paraphyly in several genera, notably Laportea, Urera, Boehmeria, Parietaria, Pellionia, and Pouzolzia. However, few studies have translated these molecular insights into a revised taxonomy. This study aimed to provide a robust, updated classification for Urticaceae by: a) increasing taxon and genomic locus sampling through the integration of newly generated sequence data with previously published datasets; and b) incorporating morphological data to support a revised delimitation of tribes and genera, and to establish a new linear sequence for the family. We also sought to identify remaining taxonomic challenges. Using Sanger and Angiosperms353 sequence data, we constructed a phylogenetic framework for 57 out of 59 currently accepted genera. We also assessed the phylogenetic informativeness of 57 morphological characters by mapping them onto the phylogeny. Our analyses support the delimitation of 61 monophyletic genera and an infrafamilial classification comprising seven tribes, two of which we describe as new: Myriocarpeae and Leukosykeae. We provide a revised linear sequence for the family. Our classification reinstates several names previously treated as synonyms (Fleurya, Leptocnide, Margarocarpus, Polychroa, Scepocarpus, Sceptrocnide), places several genera in synonymy (Hemistylus and Rousselia under Pouzolzia; Hesperocnide under Urtica; Gesnouinia and Soleirolia under Parietaria), and proposes the recognition of two new genera, Muimar gen. nov. and Pouzolziella gen. nov., to accommodate Boehmeria nivea and Pouzolzia australis, respectively. Mapping morphological characters onto the phylogeny indicates that while most states are homoplastic at the family level, their combination is valuable for recognizing genera. Geographic character mapping suggests a high degree of spatial conservatism at the genus rank. Our dated ultrametric tree suggests an origin for Urticaceae in Indomalaya during the mid-Cretaceous, followed by establishment in the Laurasian boreotropical flora and subsequent dispersal to the neotropics and Africa. Once classified within an evolutionary framework we believe that the Urticaceae represent a valuable study system in evolutionary biology for investigating transitions across biomes, the drivers of floral trait evolution, and intrinsic speciation mechanisms. New tribes: --Leukosykeae, Myriocarpeae New genera: --Muimar, Pouzolziella

evolutionary biology↗

bioRxiv2025

AI-based prediction of herbarium sequencing success across the plant tree of life

DNA recovered from herbarium specimens represents a vital asset in botanical research, playing a pivotal role in unravelling the evolution, diversity, and ecological dynamics of plants. Despite its importance, challenges such as fragmented DNA and insufficient sequencing yields render molecular data retrieval a high-risk and costly endeavour involving the use of non-replaceable herbarium specimens. Here, we propose a framework based on Artificial Intelligence (AI) to forecast the success of genomic DNA extraction suitable for sequencing from herbarium samples. Our model integrates morphological characteristics and sample colour derived from scanned herbarium images, metadata including sample age and locality, and DNA quantity measurements of samples. We train a deep learning algorithm with ca. 2,000 specimens that have been digitized and sequenced in the framework of the Plant and Fungal Trees of Life (PAFTOL) Project, spanning from year 1832 to the present. As training datasets increase with ongoing digitization and genomic sequencing efforts, our AI predictive model can support researchers in selecting the herbarium samples with the highest likelihood of yielding high-quality genomic DNA from amongst a vast array of globally distributed candidate specimens. Our approach enhances the contribution of herbarium-derived DNA in large-scale studies and facilitates the utilisation of historical collections for a deeper understanding of plant evolution and ecology, with implications for conservation.

plant biology↗

bioRxiv2024

Early Cretaceous Origin and Evolutionary History of Palms (Arecaceae) inferred from 1,033 Nuclear Genes and a New Synthesis of Fossil Evidence

AO_SCPLOWBSTRACTC_SCPLOWTropical rainforests are home to almost half of all known plant diversity, yet a shortfall in tropical plant phylogenetic hypotheses is hindering our understanding of how rainforests have formed and adapted to past global changes. Phylogenetic and historical biogeographic evidence from key rainforest lineages, including palms (Arecaceae), are required to illuminate the history of these ecosystems. However, our current understanding of the palm tree of life is based on uneven sampling of data from the plastid and nuclear genome, and numerous palm genera and palm fossils have been described or revised over the past decade, casting doubt on many palm relationships, ages and ancestral ranges inferred in previous studies. Here, we infer the phylogenetic relationships of all palm genera based on data from 1,033 nuclear genes generated using target sequence capture. Our palm tree of life is highly resolved and supported. Remaining areas of ambiguity reflect the complex dynamics of palm evolution, including many rapid diversification events in subfamily Arecoideae and putative cases of ancient reticulation throughout the family. We review the phylogenetic placement and age of hundreds of palm fossils and use a vetted selection to estimate divergence times and ancestral ranges for all palm genera. We show that the family is older than previously thought, likely first diversifying in the Early Cretaceous in Laurasia, and that three quarters of the genera had originated by the Oligocene. The early spread of palms across the world involved at least 40 long-distance dispersals across oceanic gaps. Dispersals away from northern latitudes vastly outnumber dispersals into these latitudes, consistent with the ancient affinity of palms for megathermal climates, and suggesting that global cooling during the Oligocene was a major constraint on early palm distribution. Our dated phylogenomic tree and curated fossil dataset provide a new foundation for evolutionary studies on palms, opening the door to deeper research on the rainforest biome in which they thrive.

evolutionary biology↗

bioRxiv2024

Towards a phylogenomic classification of Magnoliidae

PremiseMagnoliidae are a strongly supported clade of angiosperms. Previous phylogenetic studies based primarily on analyses of a limited number of mostly plastid markers have led to the current classification of magnoliids into four orders and 18 families. However, uncertainty remains regarding the placement of several families. MethodsHere we present the first comprehensive phylogenomic analysis of Magnoliidae as a whole, sampling 235 species from 199 (74%) genera and representing all families and most previously accepted subfamilies and tribes. We analyze newly generated data from the Angiosperms353 probe set using both coalescent and concatenation analyses and testing the impact of multiple filtering and alignment strategies. ResultsWhile our results generally provide further support for previously established phylogenetic relationships in both magnoliids as a whole and large families including Annonaceae and Lauraceae, they also provide new evidence for previously ambiguous relationships. In particular, we find support for the position of Hydnoraceae as sister to the remainder of Piperales and, for the first time, resolve the backbone of relationships among most genera of Myristicaceae. ConclusionsAlthough some of our results are limited by low gene recovery for a number of taxa and significant gene tree conflict for some relationships, this study represents a significant step towards reconstructing the evolutionary history of a major lineage of angiosperms. Based on these results, we present an updated phylogenetic classification for Magnoliidae, recognizing 21 families, summarizing previously established subfamilies and tribes, and describing new tribes for Myristicaceae.

evolutionary biology↗

bioRxiv2023

A novel phylogenomics pipeline reveals complex pattern of reticulate evolution in Cucurbitales

High-throughput sequencing data, such as target capture, RNA-Seq, genome skimming, and high-depth whole genome sequencing, are used for phylogenomic analyses. Integrating these mixed data types into a single phylogenomic dataset requires several bioinformatic tools and significant computational resources. Here, we present CAPTUS, a novel pipeline to analyze mixed data efficiently. CAPTUS assembles these data types, searches for loci of interest, and produces paralog-filtered alignments. If reference target loci are not available for the studied taxon, CAPTUS can also be used to discover new putative homologs via sequence clustering. Compared to other software, CAPTUS allows the recovery of a greater number of more complete loci across more species. We apply CAPTUS to assemble a comprehensive dataset, comprising the four types of sequencing data for the angiosperm order Cucurbitales, a clade of about 3,100 species in eight mainly tropical plant families, including begonias (Begoniaceae) and gourds (Cucurbitaceae). Our phylogenomic results support the currently accepted circumscription of Cucurbitales except for the position of the holoparasitic Apodanthaceae, which group with Rafflesiaceae in Malpighiales. A subset of mitochondrial gene regions supports the earlier divergence of Apodanthaceae in Cucurbitales. However, the nuclear regions and majority of mitochondrial regions place Apodanthaceae in Malpighiales. Within Cucurbitaceae, we confirm the monophyly of all currently accepted tribes but also reveal hybridization and incomplete lineage sorting both in Cucurbitales and within Cucurbitaceae. We show that contradicting results among earlier phylogenetic studies in Cucurbitales can be reconciled when accounting for gene tree conflict and demonstrate the efficiency of CAPTUS for complex datasets.

bioinformatics↗

bioRxiv2023

The Origin And Speciation Of Orchids

Orchids constitute one of the most spectacular radiations of flowering plants. However, their geographical origin, historical spread across the globe, and hotspots of speciation remain uncertain due to the lack of a broad phylogenomic framework. We present a new Orchidaceae phylogeny based on high-throughput and Sanger sequencing datasets, covering all five subfamilies, 17/22 tribes, 40/49 subtribes, 285/736 genera, and [~]7% (1,921) of the currently 29,524 accepted species. We then use it to infer geographic range evolution, diversity, and speciation patterns by adding curated geographical distribution data through the World Checklist of Vascular Plants. Orchids most recent common ancestor is traced back to the Late Cretaceous in Laurasia. The modern Southeast Asian range of subfamily Apostasioideae is interpreted as relictual, matching the history of numerous clades that went extinct at higher latitudes following the global climate cooled during the Oligocene. Despite their ancient origins, modern orchid species diversity mainly originated over the last 5 Ma, with the fastest speciation rates found in south-eastern Central America. Our results substantially alter our understanding of the geographic origin of orchids, previously proposed as Australian, and further pinpoint the role of Central American as a region of recent and explosive speciation.

evolutionary biology↗

bioRxiv2022

Global Phylogeny of the Brassicaceae Provides Important Insights into Gene Discordance

The mustard family (Brassicaceae) is a scientifically and economically important family, containing the model plant Arabidopsis thaliana and numerous crop species that feed billions worldwide. Despite its relevance, most published family phylogenies are incompletely sampled, generally contain massive polytomies, and/or show incongruent topologies between datasets. Here, we present the most complete Brassicaceae genus-level family phylogenies to date (Brassicaceae Tree of Life, or BrassiToL) based on nuclear (>1,000 genes, almost all 349 genera and 53 tribes) and plastome (60 genes, 79% of the genera, all tribes) data. We found cytonuclear discordance between nuclear and plastome-derived phylogenies, which is likely a result of rampant hybridisation among closely and more distantly related species, and highlight rogue taxa. To evaluate the impact of this rampant hybridisation on the nuclear phylogeny reconstruction, we performed four different sampling routines that increasingly removed variable data and likely paralogs. Our resulting cleaned subset of 297 nuclear genes revealed high support for the tribes, while support for the main lineages remained relatively low. Calibration based on the 20 most clock-like nuclear genes suggests a late Eocene to late Oligocene icehouse origin of the family. Finally, we propose five new or re-established tribes, including the recognition of Arabidopsideae, a monotypic tribe to accommodate Arabidopsis. With a worldwide community of thousands of researchers working on this family, our new, densely sampled family phylogeny will be an indispensable tool to further highlight Brassicaceae as an excellent model family for studies on biodiversity and plant biology.

evolutionary biology↗

bioRxiv2021

A Comprehensive Phylogenomic Platform for Exploring the Angiosperm Tree of Life

The tree of life is the fundamental biological roadmap for navigating the evolution and properties of life on Earth, and yet remains largely unknown. Even angiosperms (flowering plants) are fraught with data gaps, despite their critical role in sustaining terrestrial life. Today, high-throughput sequencing promises to significantly deepen our understanding of evolutionary relationships. Here, we describe a comprehensive phylogenomic platform for exploring the angiosperm tree of life, comprising a set of open tools and data based on the 353 nuclear genes targeted by the universal Angiosperms353 sequence capture probes. This paper (i) documents our methods, (ii) describes our first data release and (iii) presents a novel open data portal, the Kew Tree of Life Explorer (https://treeoflife.kew.org). We aim to generate novel target sequence capture data for all genera of flowering plants, exploiting natural history collections such as herbarium specimens, and augment it with mined public data. Our first data release, described here, is the most extensive nuclear phylogenomic dataset for angiosperms to date, comprising 3,099 samples validated by DNA barcode and phylogenetic tests, representing all 64 orders, 404 families (96%) and 2,333 genera (17%). Using the multi-species coalescent, we inferred a "first pass" angiosperm tree of life from the data, which totalled 824,878 sequences, 489,086,049 base pairs, and 532,260 alignment columns. The tree is strongly supported and highly congruent with existing taxonomy, while challenging numerous hypothesized relationships among orders and placing many genera for the first time. The validated dataset, species tree and all intermediates are openly accessible via the Kew Tree of Life Explorer. This major milestone towards a complete tree of life for all flowering plant species opens doors to a highly integrated future for angiosperm phylogenomics through the systematic sequencing of standardised nuclear markers. Our approach has the potential to serve as a much-needed bridge between the growing movement to sequence the genomes of all life on Earth and the vast phylogenomic potential of the worlds natural history collections.

evolutionary biology↗

bioRxiv2021

Tree phylogenetic diversity supports nature's contributions to people, but is at risk from human population growth

There is growing evidence for a link between biodiversity and ecosystem function, and for a correlation between human population and the species diversity of plants and animals in a region. Here, we suggest these relationships might not be independent. Using a comprehensive phylogeny of southern African trees and structural equation modelling, we show that human population density correlates with tree phylogenetic diversity and show that this relationship is stronger than the correlation with species richness alone. Further, we demonstrate that areas high in phylogenetic diversity support a greater diversity of ecosystem goods and services, indicating that the evolutionary processes responsible for generating variation among living organisms are also key to the provisioning of natures contributions to people. Our results raise the intriguing possibility that the history of human settlement in southern Africa may have been shaped, in part, by the evolutionary history of its tree flora. However, the correlation between human population and tree diversity generates a conflict between people and nature. Our study suggests that future human population growth may threaten the contributions to people provided by intact and phylogenetically diverse ecosystems.

ecology↗

bioRxiv2020

Hundreds of nuclear and plastid loci yield insights into orchid relationships

Premise of the studyEvolutionary relationships in the species-rich Orchidaceae have historically relied on organellar DNA sequences and limited taxon sampling. Previous studies provided a robust plastid-maternal phylogenetic framework, from which multiple hypotheses on the drivers of orchid diversification have been derived. However, the extent to which the maternal evolutionary history of orchids is congruent with that of the nuclear genome has remained uninvestigated. MethodsWe inferred phylogenetic relationships from 294 low-copy nuclear genes sequenced/obtained using the Angiosperms353 universal probe set from 75 species representing 69 genera, 16 tribes and 24 subtribes. To test for topological incongruence between nuclear and plastid genomes, we constructed a tree from 78 plastid genes, representing 117 genera, 18 tribes and 28 subtribes and compared them using a co-phylogenetic approach. The phylogenetic informativeness and support of the Angiosperms353 loci were compared with those of the 78 plastid genes. Key ResultsPhylogenetic inferences of nuclear datasets produced highly congruent and robustly supported orchid relationships. Comparisons of nuclear gene trees and plastid gene trees using the latest co-phylogenetic tools revealed strongly supported phylogenetic incongruence in both shallow and deep time. Phylogenetic informativeness analyses showed that the Angiosperms353 genes were in general more informative than most plastid genes. ConclusionsOur study provides the first robust nuclear phylogenomic framework for Orchidaceae plus an assessment of intragenomic nuclear discordance, plastid-nuclear tree incongruence, and phylogenetic informativeness across the family. Our results also demonstrate what has long been known but rarely documented: nuclear and plastid phylogenetic trees are not fully congruent and therefore should not be considered interchangeable.

evolutionary biology↗

bioRxiv2020

Phylogeny of the species-rich Pilea Lindl. (Urticaceae) supports its revised delimitation and infrageneric classification, including the resurrection of Achudemia Blume

ABSTRACTPilea Lindl., with 933 published names is the largest genus within the Urticaceae. Pilea was last monographed in 1869 and whilst the monophyly of the genus has been proposed by previous authors, this has been based on incomplete taxon sampling and the failure to resolve the position of key taxa. We aimed to generate a robust phylogeny for Pilea and allied genera that could provide a framework for testing the monophyly of Pilea, revising its delimitation and for answering broader scientific questions about this species-rich genus. To do so, we sought to sample taxa representative of previous infrageneric classifications and with anomalous inflorescences or flower configurations and to use the resulting phylogeny to evaluate the delimitation of Pilea and to establish an infrageneric classification. In addition, we included a representative of the Polynesian genus Haroldiella which, morphologically, is very similar to Pilea. Using Sanger sequence data from two plastid and one nuclear regions we constructed a phylogeny using Bayesian Inference, Maximum Likelihood and Maximum Parsiomony approaches. We used our phylogeny to evaluate the informativness of 19 morphological traits and applied both to delimit a monophyletic genus and infrageneric sections. Our results recovered Pilea as paraphyletic with respect to Lecanthus, a consequence of the recovery of a monophyletic clade comprising sections Achudemia and Smithiella, neither of which had been adequately sampled in previous studies. We also recovered Pilea as polyphyletic with respect to Haroldiella. We identified isomery between male and female flowers, flower part number and male sepal arrangement as being phylogenetically informative traits that can be used to delimit two genera, Achudemia, including section Smithiella, recovered as sister to Lecanthus, and Pilea, including Haroldiella, recovered as sister to both. On the basis of our evaluation of both morphological traits and phylogenetic relationships we propose a new infrageneric classification for the genus comprising seven sections, five of which we describe for the first time, § Trimeris Y.G.Wei & A.K.Monro, § Lecanthoides C.J.Chen, § Angulata L.F.Fu & Y.G.Wei, § Tetrameris C.J.Chen, § Verrucosa L.F.Fu & Y.G.Wei, § Plataniflora L.F.Fu & Y.G.Wei and § Leiocarpa L.F.Fu & Y.G.Wei. We also identify a trend of decreasing merism and fruit size, and increasing species-richness as Pilea diverges. In addition, we recover strong geographical structure within our phylogeny, sufficient to propose that Pilea originated in the IndoMalaya biogeographic domain.Competing Interest StatementThe authors have declared no competing interest.View Full Text

plant biology↗

bioRxiv2020

Repeated parallel losses of inflexed stamens in Moraceae: phylogenomics and generic revision of the tribe Moreae and the reinstatement of the tribe Olmedieae (Moraceae)

We present a densely-sampled phylogenomic study of the mulberry tribe (Moreae, Moraceae), an economically important clade with a global distribution, revealing multiple losses of inflexed stamens, a character traditionally used to circumscribe Moreae. Inflexed stamens facilitate ballistic pollen release and are associated with wind pollination, and the results presented here suggest that losses of this character state may have evolved repeatedly in Moraceae. Neither Moreae nor several of its major genera (Morus, Streblus, Trophis) were found to be monophyletic. A revised system for a monophyletic Moreae is presented, including the reinstatement of the genera Ampalis, Maillardia, Taxotrophis, and Paratrophis, and the recognition of the new genus Afromorus, based on Morus subgenus Afromorus. Pseudostreblus is reinstated and transferred to the Parartocarpeae, and Sloetiopsis is reinstated and transferred to the Dorstenieae. The tribe Olmediae is reinstated, replacing the Castilleae, owing to the reinstatement of the type genus Olmedia, and its exclusion from Moreae. Streblus s.s. is excluded from Moreae and transferred to the Olmediae, which is characterized primarily by involucrate inflorescences without regard to stamen position. Eight new combinations are made.

plant biology↗

bioRxiv2019

A large-scale species level dated angiosperm phylogeny for evolutionary and ecological analyses

Phylogenies are a central and indispensable tool for evolutionary and ecological research. Even though most angiosperm families are well investigated from a phylogenetic point of view, there are far less possibilities to carry out large-scale meta-analyses at order level or higher. Here, we reconstructed a large-scale dated phylogeny including nearly 1/8th of all angiosperm species based on two plastid barcoding genes, matK and rbcL. Novel sequences were generated for several species, while the rest of the data were mined from GenBank. The resulting tree was dated using 56 angiosperm fossils as calibration points. The resulting megaphylogeny is one of the largest dated phylogenetic tree of angiosperms yet, consisting of 36,101 sampled species, representing 8,399 genera, 426 families and all orders. This novel framework will be useful to investigate different broad scale research questions in ecological and evolutionary biology.

evolutionary biology↗

bioRxiv2018

A Universal Probe Set for Targeted Sequencing of 353 Nuclear Genes from Any Flowering Plant Designed Using k-medoids Clustering

Sequencing of target-enriched libraries is an efficient and cost-effective method for obtaining DNA sequence data from hundreds of nuclear loci for phylogeny reconstruction. Much of the cost associated with developing targeted sequencing approaches is preliminary data needed for identifying orthologous loci for probe design. In plants, identifying orthologous loci has proven difficult due to a large number of whole-genome duplication events, especially in the angiosperms (flowering plants). We used multiple sequence alignments from over 600 angiosperms for 353 putatively single-copy protein-coding genes to design a set of targeted sequencing probes for phylogenetic studies of any angiosperm lineage. To maximize the phylogenetic potential of the probes while minimizing the cost of production, we introduce a k-medoids clustering approach to identify the minimum number of sequences necessary to represent each coding sequence in the final probe set. Using this method, five to 15 representative sequences were selected per orthologous locus, representing the sequence diversity of angiosperms more efficiently than if probes were designed using available sequenced genomes alone. To test our approximately 80,000 probes, we hybridized libraries from 42 species spanning all higher-order lineages of angiosperms, with a focus on taxa not present in the sequence alignments used to design the probes. Out of a possible 353 coding sequences, we recovered an average of 283 per species and at least 100 in all species. Differences among taxa in sequence recovery could not be explained by relatedness to the representative taxa selected for probe design, suggesting that there is no phylogenetic bias in the probe set. Our probe set, which targeted 260 kbp of coding sequence, achieved a median recovery of 137 kbp per taxon in coding regions, a maximum recovery of 250 kbp, and an additional median of 212 kbp per taxon in flanking non-coding regions across all species. These results suggest that the Angiosperms353 probe set described here is effective for any group of flowering plants and would be useful for phylogenetic studies from the species level to higher-order lineages, including all angiosperms.

evolutionary biology↗