Premise Of The Study: Polyploidization is a common and recurring phenomenon in plants and is often thought to be a mechanism of "instant speciation". Whether polyploidization is associated with the formation of new species (cladogenesis) or simply occurs over time within a lineage (anagenesis), however, has never been assessed systematically.
Methods: We tested this hypothesis using phylogenetic and karyotypic information from 235 plant genera (mostly angiosperms). We first constructed a large database of combined sequence and chromosome number data sets using an automated procedure. We then applied likelihood models (ClaSSE) that estimate the degree of synchronization between polyploidization and speciation events in maximum likelihood and Bayesian frameworks.
Key Results: Our maximum likelihood analysis indicated that 35 genera supported a model that includes cladogenetic transitions over a model with only anagenetic transitions, whereas three genera supported a model that incorporates anagenetic transitions over one with only cladogenetic transitions. Furthermore, the Bayesian analysis supported a preponderance of cladogenetic change in four genera but did not support a preponderance of anagenetic change in any genus.
Conclusions: Overall, these phylogenetic analyses provide the first broad confirmation that polyploidization is temporally associated with speciation events, suggesting that it is indeed a major speciation mechanism in plants, at least in some genera.
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http://dx.doi.org/10.3732/ajb.1600108 | DOI Listing |
Mol Ecol
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Department of Anatomy, University of Otago, Dunedin, New Zealand.
In a changing environment, vacant niches can be filled either by adaptation of local taxa or range-expanding invading species. The relative tempo of these patterns is of key interest in the modern age of climate change. Aotearoa New Zealand has been a hotspot of biogeographic research for decades due to its long-term isolation and dramatic geological history.
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January 2025
Institute of Chemical Technology, Vietnam Academy of Science and Technology, 1A TL29 Street, Thanh Loc Ward, District 12, HCM City, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Street, Cau Giay District, Hanoi, Viet Nam. Electronic address:
Whole-cell bioreactors equipped with external physico-chemical sensors have gained attention for real-time toxicity monitoring. However, deploying these systems in practice is challenging due to potential interference from unknown wastewater constituents with liquid-contacted sensors. In this study, a novel approach using a bioreactor integrated with a non-dispersive infrared CO₂ sensor for both toxicity detection and real-time monitoring of microbial growth phases was successfully demonstrated.
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Systematics and Evolution of Vascular Plants (UAB), Associated Unit to CSIC by IBB, Departament de Biologia Animal, Biologia Vegetal i Ecologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
Colonization and diversification processes are responsible for the distinctiveness of island biotas, with Madagascar standing out as abiodiversity hotspot exceptionally rich in species and endemism. Regardless of its significance, the evolutionary history and diversification drivers of Madagascar's flora remain understudied. Here we focus on Helichrysum (Compositae, Gnaphalieae) to investigate the evolutionary and biogeographic origins of the Malagasy flora.
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January 2025
Department of Biology and Wildlife, University of Alaska Museum, Fairbanks, Alaska, USA.
The application of high-throughput sequencing to phylogenetic analyses is allowing authors to reconstruct the true evolutionary history of species. This work can illuminate specific mechanisms underlying divergence when combined with analyses of gene flow, recombination and selection. We conducted a phylogenomic analysis of Catharus, a songbird genus with considerable potential for gene flow, variation in migratory behaviour and genomic resources.
View Article and Find Full Text PDFMol Phylogenet Evol
December 2024
Department of Earth and Environmental Sciences, Rutgers University, Newark, NJ, USA.
Species relationships and speciation have traditionally been represented by phylogenetic trees, but not all evolutionary histories fit into bifurcating divergence models. Introgressive hybridization challenges this assumption by sometimes [or maybe often] leading to mitochondrial introgression, wherein one species' mitochondrial genome is entirely replaced by another's (mitochondrial capture). Such processes result in mitonuclear discrepancies, complicating species delimitation and phylogenetic inference.
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