Biology subjects

de la Estrella, M.

Publications and source records attributed to de la Estrella, M..

5 recordsLinked to original sources

bioRxiv2025

Understanding Patterns of Interploidy Admixture in Polyploid Complexes: Insights from Thymus sect. Mastichina (Lamiaceae)

Understanding gene flow between ploidy levels in polyploid complexes is essential for species delimitation and conservation. This study explores evolutionary dynamics in the polyploid complex Thymus sect. Mastichina (Lamiaceae), comprising three taxa: T. mastichina subsp. mastichina, T. mastichina subsp. donyanae, and the endangered T. albicans. Using Hyb-Seq data, phylogenomics (nuclear orthologs), and population genomics (SNPs), we confirm the section consists of two sister groups with distinct ploidy levels: a diploid and a tetraploid one. The tetraploid group shows low genetic differentiation among its populations, probably indicating rapid expansion across diverse environments. In contrast, the diploid group exhibits more complex genetic structuring, potentially shaped by geomorphology, interploidy introgression, and incipient isolation. Four diploid subgroups (Algarve, Cadiz, Donana, and Hercynian) are identified, with reticulate evolution. The dense reticulation observed is compatible with incomplete lineage sorting in diploid lineages, due to recent and rapid divergence events. Phylogeographic analyses suggest isolation-by-distance, with two major riverbeds maybe playing a role in shaping genetic differentiation, while interploidy gene flow detected could have facilitated ancient and/or ongoing admixture between diploid and tetraploid lineages, despite geographic isolation. These findings highlight cryptic genetic diversity and emphasise the need for an integrative taxonomy that includes multiple lines of evidence: morphological, cytological, genomic, and ecological. Conservation efforts should prioritise protecting the four diploid subgroups, aided by flow cytometry, since they may harbour critical adaptive potential to both specific habitat types and/or environmental conditions. This work contributes to advancing our knowledge of evolution in polyploid complexes, by combining genomic approaches and highlighting cryptic diversity in Thymus species. Future research should investigate morphometric and chemical data, hybridisation events, divergence times, diversification dynamics, and relationships with other Thymus species to further understand polyploid evolution and its impact on biodiversity.

evolutionary biology↗

bioRxiv2025

Phylogenetic biome niche conservatism underlies the evolution of forest paleoendemic legume trees in tropical Africa

Niche conservatism is prevalent during the evolution of plant lineages. However, inferring biome niche lability and its impact on tropical tree species diversification is currently limited. To better understand biome niche lability and its effect on diversification rates, we analyzed an endemic lineage of African tropical trees, testing whether biome niche type (forest vs savanna) and biome lability are non-randomly distributed. We reconstructed a time-calibrated phylogeny of the Berlinia clade (16 genera, ca 201 species) using 140 nuclear genes, 75% of its extant species, and eight fossil calibrations. We also analyzed the phylogenetic signal of biome shifts across the group and its effect on diversification and extinction rates. We found the forest biome as the ancestral condition and a directional shift from forest to savanna (no reversals). The forest biome type is conserved in the Berlinia clade, but the lability to shift biomes is randomly distributed in the group. We did not find evidence that biome shift was associated with higher diversification or lower extinction rates. Our analyses identified five paleoendemic genera that have persisted solely in the forest biome since the Eocene. These paleoendemic and forest-restricted lineages are potentially more susceptible to habitat alterations of human related activities and future climate change, due to perhaps an innate limitation to adapt to new habitat types.

evolutionary biology↗

bioRxiv2021

The diversification of Pterocarpus (Leguminosae: Papilionoideae) was influenced by biome-switching and infrequent long-distance dispersal

AimPhenotypes which evolved for dispersal over ecological timescales may lead to significant macroevolutionary consequences, such as infrequent long-distance dispersal and diversification in novel biomes. We aimed to reconstruct the phylogenetic history of Pterocarpus (Leguminosae/ Fabaceae) to assess whether seed dispersal phenotypes and biome switching explain the current biogeographical patterns of this group. LocationPantropical TaxonThe Pterocarpus clade, particularly Pterocarpus (Leguminosae/Fabaceae) MethodsWe sequenced ~300 nuclear loci captured using Angiosperms-353, a genomic bait set for flowering plants, from which we generated a time-calibrated phylogenomic tree. To corroborate this, we also generated a time-calibrated phylogenetic tree from data-mined Sanger-sequencing data. We then collated distribution data and fruit dispersal morphology traits to compare trait-dependent and trait-independent biogeographical models, allowing us to assess whether dispersal traits influenced the spatio-temporal evolution of Pterocarpus. Finally, using the results of these model tests, we estimated the ancestral ranges and biomes of Pterocarpus species to better understand their biogeographical history, and assessed the degree and direction of biome switching over the course of Pterocarpus diversification history. ResultsWe recovered well-supported phylogenetic relationships within Pterocarpus, within which there were two subclades - one Neotropical and the other Palaeotropical. Our divergence date estimates suggested that Pterocarpus largely diversified from around 12 Ma, during the Miocene. Trait-dependent biogeographical models were rejected for both range and biome evolution within Pterocarpus, but models parameterising dispersal were supported. Pterocarpus ancestral node shared a range across the new-world and old-world tropics, followed by divergence into two clades, one palaeotropical and one neotropical. Biome switching occurred most frequently into rainforest and grassland. Main conclusionsOverall, our analyses suggest that Pterocarpus underwent infrequent cross-continental dispersal and establishment into novel biomes. While this was minimally impacted by fruit dispersal syndromes, biome switching precipitated by long-distance dispersal and environmental change have played an important role in diversification within Pterocarpus since the Miocene.

evolutionary biology↗

bioRxiv2019

Introgression in Brownea suggests that reticulate evolution contributes to Amazonian tree diversity

Hybridization has the potential to generate or homogenize biodiversity and is a particularly common phenomenon in plants, with an estimated 25% of species undergoing inter-specific gene flow. However, hybridization in Amazonias megadiverse tree flora was assumed to be extremely rare despite extensive sympatry between closely related species, and its role in diversification remains enigmatic because it has not yet been examined empirically. Using members of a dominant Amazonian tree family (Brownea, Fabaceae) as a model to address this knowledge gap, our study recovered extensive evidence of hybridization among multiple lineages across phylogenetic scales. More specifically, our results uncovered several historical introgression events between Brownea lineages and indicated that gene tree incongruence in Brownea is best explained by introgression, rather than solely by incomplete lineage sorting. Furthermore, investigation of recent hybridization using [~]19,000 ddRAD loci recovered a high degree of shared variation between two Brownea species which co-occur in the Ecuadorian Amazon. Our analyses also showed that these sympatric lineages exhibit homogeneous rates of introgression among loci relative to the genome-wide average, implying a lack of selection against hybrid genotypes and a persistence of hybridization over time. Our results demonstrate that gene flow between multiple Amazonian tree species has occurred across temporal scales, and contrasts with the prevailing view of hybridizations rarity in Amazonia. Overall, our results provide novel evidence that reticulate evolution influenced diversification in part of the Amazonian tree flora, which is the most diverse on Earth.

evolutionary biology↗

bioRxiv2019

Phylogenomics within the Anthonotha clade (Detarioideae, Leguminosae) reveals a high diversity in floral trait shifts and a general trend towards organ number reduction

Detarioideae is well known for its high diversity of floral traits, including flower symmetry, number of organs, and petal size and morphology. This diversity has been characterized and studied at higher taxonomic levels, but limited analyses have been performed among closely related genera with contrasting floral traits due to the lack of fully resolved phylogenetic relationships. Here, we used four representative transcriptomes to develop an exome capture bait for the entire subfamily and applied it to the Anthonotha clade using a complete data set (61 specimens) representing all extant floral diversity. Our phylogenetic analyses recovered congruent topologies using ML and Bayesian methods. The genus Anthonotha was recovered as monophyletic contrary to the remaining three genera (Englerodendron, Isomacrolobium and Pseudomacrolobium), which form a monophyletic group sister to Anthonotha. We inferred a total of 35 transitions for the seven floral traits (pertaining to flower symmetry, petals, stamens and staminodes) that we analyzed, suggesting that at least 30% of the species in this group display transitions from the ancestral condition reconstructed for the Anthonotha clade. The main transitions were towards a reduction in the number of organs (petals, stamens and staminodes). Despite the high number of transitions, our analyses indicate that the seven characters are evolving independently in these lineages. Petal morphology is the most labile floral trait with a total of seven independent transitions in number and seven independent transitions to modification in petal types. The diverse petal morphology along the dorsoventral axis of symmetry within the flower is not associated with differences at the micromorphology of petal surface, suggesting that in this group all petals within the flower might possess the same petal identity at the molecular level. Our results provide a solid evolutionary framework for further detailed analyses of the molecular basis of petal identity.

evolutionary biology↗