The latitudinal diversity gradient has been hypothesized to reflect past evolutionary dynamics driven by climatic niche conservation during cladogenesis, i.e. the tropical conservatism hypothesis. Here we show that the species diversity of treefrogs (Hylidae) across the western hemisphere is actually independent of evolutionary niche dynamics. We evaluated three key predictions of the tropical conservatism hypothesis that relate to the relationships between climate, species richness and the phylogenetic structure of regional treefrog faunas across the continental Americas. Species composition was dependent on the inability of some lineages to evolve cold tolerance, but the actual number of species in a region was strongly predicted by precipitation, not temperature. Moreover, phylogenetic structure was independent of precipitation. Thus, species in low-richness areas were no more closely related than species in highly diverse regions. These results provide no support for the tropical conservatism hypothesis. Instead, they show that regional species composition and richness are constrained by different climatic components, demonstrating that global biodiversity gradients can be independent of niche stasis during cladogenesis.
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http://dx.doi.org/10.1111/j.1461-0248.2008.01260.x | DOI Listing |
Risk Manag Healthc Policy
December 2024
Department of Health Management and Policy, Faculty of Health Sciences, American University of Beirut, Beirut, Lebanon.
The interrelationality of health and peace is complex, multifactorial, and imbued with political and economic challenges. Peace and health outcomes reflect shared fundamental values related to the achievement of a balanced holistic condition on the individual and collective level. This causal relationship between social inequity and health requires special attention be paid to the impact of political instability and structural violence on undermining health systems in conflict zones.
View Article and Find Full Text PDFRev Bras Bot
December 2024
Institut de Recherche en Biologie Végétale and Département de Sciences Biologiques, Université de Montréal, Montréal, QC H1X 2B2 Canada.
Unlabelled: Some plant lineages remain within the same biome over time (biome conservatism), whereas others seem to adapt more easily to new biomes. The c. 398 species (14 genera) of subfamily Cercidoideae (Leguminosae or Fabaceae) are found in many biomes around the world, particularly in the tropical regions of South America, Asia and Africa, and display a variety of growth forms (small trees, shrubs, lianas and herbaceous perennials).
View Article and Find Full Text PDFNature
December 2024
Institute of Translational Medicine, ETH Zurich, Zurich, Switzerland.
Nat Commun
November 2024
Center for Innovative Drug Development and Therapeutic Trials for Africa (CDT-Africa), College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
The health, economic, and social burden of neglected tropical diseases (NTDs) in Africa remains substantial, with elimination efforts hindered by persistent sociopolitical instability, including ongoing conflicts among political and ethnic groups that lead to internal displacement and migration. Here, we explore how innovative technologies can support Africa in addressing NTDs amidst such instability, through analysis of WHO and UNHCR data and a systematic literature review. Countries in Africa facing sociopolitical instability also bear a high burden of NTDs, with the continent ranking second globally in NTD burden (33%, 578 million people) and first in internal displacement (50%, 31.
View Article and Find Full Text PDFHealth Res Policy Syst
November 2024
Department of Epidemiology, Columbia University Mailman School of Public Health, 622 West 168th Street, 8th Floor, New York, NY, 10032, United States of America.
Background: Costing and financing systematic implementation are recognized barriers to human immunodeficiency virus (HIV) prevention. In the absence of empiric implementation and economic data, perspectives from international stakeholders involved in developing and supporting daily oral pre-exposure prophylaxis (PrEP) policy, and programs can provide critical insights for developing costed plans to support and accelerate the rollout of novel long-acting PrEP (LA-PrEP) methods, such as the monthly dapivirine vaginal ring (PrEP ring).
Methods: We interviewed stakeholders from purposively selected international organizations about anticipated PrEP-ring implementation costs, evidence gaps and key process steps for developing a costed rollout plan template (CRPT).
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