| 1. |
- Antonelli, Alexandre, 1978, et al.
(författare)
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Madagascar's extraordinary biodiversity : Evolution, distribution, and use
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 378:6623, s. 962-
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Tidskriftsartikel (refereegranskat)abstract
- Madagascar's biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar's past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting an updated and simplified map of vegetation types. We report a substantial increase of records and species new to science in recent years; however, the diversity and evolution of many groups remain practically unknown (e.g., fungi and most invertebrates). Digitization efforts are increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge and identifying gaps in our understanding, particularly as species richness corresponds closely to collection effort. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. We highlight humid forests as centers of diversity and endemism because of their role as refugia and centers of recent and rapid radiations. However, the distinct endemism of other areas, such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest, is also biologically important despite lower species richness. The documented uses of Malagasy biodiversity are manifold, with much potential for the uncovering of new useful traits for food, medicine, and climate mitigation. The data presented here showcase Madagascar as a unique " living laboratory" for our understanding of evolution and the complex interactions between people and nature. The gathering and analysis of biodiversity data must continue and accelerate if we are to fully understand and safeguard this unique subset of Earth's biodiversity.
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| 2. |
- Santangelo, James S., et al.
(författare)
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Global urban environmental change drives adaptation in white clover
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 375
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Tidskriftsartikel (refereegranskat)abstract
- Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural dines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.
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| 3. |
- Ralimanana, H., et al.
(författare)
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Madagascar’s extraordinary biodiversity: Threats and opportunities
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 378:6623
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Forskningsöversikt (refereegranskat)abstract
- Madagascar’s unique biota is heavily affected by human activity and is under intense threat. Here, we review the current state of knowledge on the conservation status of Madagascar’s terrestrial and freshwater biodiversity by presenting data and analyses on documented and predicted species-level conservation statuses, the most prevalent and relevant threats, ex situ collections and programs, and the coverage and comprehensiveness of protected areas. The existing terrestrial protected area network in Madagascar covers 10.4% of its land area and includes at least part of the range of the majority of described native species of vertebrates with known distributions (97.1% of freshwater fishes, amphibians, reptiles, birds, and mammals combined) and plants (67.7%). The overall figures are higher for threatened species (97.7% of threatened vertebrates and 79.6% of threatened plants occurring within at least one protected area). International Union for Conservation of Nature (IUCN) Red List assessments and Bayesian neural network analyses for plants identify overexploitation of biological resources and unsustainable agriculture as the most prominent threats to biodiversity. We highlight five opportunities for action at multiple levels to ensure that conservation and ecological restoration objectives, programs, and activities take account of complex underlying and interacting factors and produce tangible benefits for the biodiversity and people of Madagascar.
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| 4. |
- Sanín, M. J., et al.
(författare)
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Volcanic events coincide with plant dispersal across the Northern Andes
- 2022
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Ingår i: Global and Planetary Change. - : Elsevier BV. - 0921-8181. ; 210
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Tidskriftsartikel (refereegranskat)abstract
- Biological dispersal is increasingly seen as a primary driver of speciation across the tropical Andes. Similarly, growing evidence suggests that the Northern Andes cordilleras formed as disconnected segments, at least until the late Miocene. For montane species, this discontinuity can hinder dispersal to the different mountain segments. Hence, understanding which processes involved in mountain formation are related to species capacity to disperse between mountains is crucial to understanding Andean biogeography. Volcanic eruptions are known to affect biodiversity in different ways, but their effects on species connectivity through the creation of topographic growth remains largely unknown. Species that are distributed in the different geographic units of the Andes can be informative with respect to how and when the different mountains have formed. The wax palms, genus Ceroxylon, comprise 13 strictly Andean species of which three species complexes are widely distributed in the tropical Andes, inhabiting cloud forests at elevations of 1400–3500 m. We sequenced 129 individuals of all but one described species using target sequence capture to reconstruct the phylogenetic history of Ceroxylon. We inferred chronograms using secondary calibrations and demographic modeling, which along with ancestral area reconstructions, allowed us to estimate the relative contributions of dispersal and speciation in the diversification history of Ceroxylon. Geological samples of ignimbritic rocks record a Plio-Pleistocene volcanic eruption of great magnitude that connected the three Colombian cordilleras by increasing topographic growth where a former lowland pass disconnected the northern mountain segments. The timing of this topographic change coincides with an increase in dispersal events to the Western and Central Cordilleras of Colombia from adjacent Andean cordilleras (i.e. the Andes outside of Colombia). Taken together, we determine that local topographic growth resulting from volcanic eruptions played a key role in augmenting mountain chain connectivity by uplift and valley filling, which favored dispersal throughout the Northern Andes. We can spatially and temporally link a biogeographical distribution pattern to a traceable geological event. © 2022 Elsevier B.V.
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