RESUMEN

The evolution of body size within and among species is predicted to be influenced by multifarious environmental factors. However, the specific drivers of body size variation have remained difficult to understand because of the wide range of proximate factors that covary with ectotherm body sizes across populations with varying local environmental conditions. Here, we used female Eremias argus lizards collected from different populations across their wide range in China, and constructed linear mixed models to assess how climatic conditions and/or available resources at different altitudes shape the geographical patterns of lizard body size across altitude. Lizard populations showed significant differences in body size across altitudes. Furthermore, we found that climatic and seasonal changes along the altitudinal gradient also explained variations in body size among populations. Specifically, body size decreased with colder and drier environmental conditions at high altitudes, reversing Bergmann's rule. Limited resources at high altitudes, measured by the low vegetative index, may also constrain body size. Therefore, our study demonstrates that multifarious environmental factors could strongly influence the intraspecific variation in organisms' body size.

RESUMEN

The emerging and re-emerging vector-borne diseases transmitted by key freshwater organisms have remained a global concern. As one of the leading biodiversity hotspots, the African ecoregion is suggested to harbour the highest number of freshwater organisms globally. Among the commonly found organisms in the African ecoregion are mosquitoes and snails, with a majority of their life cycle in freshwater, and these freshwater organisms can transmit diseases or serve as carriers of devastating diseases of public health concerns. However, synthetic studies to link the evident abundant presence and wide distribution of these vectors across the freshwater ecosystems in Africa with the increasing emerging and re-emerging vector-borne diseases in Africa are still limited. Here, we reviewed documented evidence on vector-borne diseases and their transmission pathways in Africa to reduce the knowledge gap on the factors influencing the increasing emerging and re-emerging vector-borne diseases across Africa. We found the population distributions or abundance of these freshwater organisms to be increasing, which is directly associated with the increasing emerging and re-emerging vector-borne diseases across Africa. Furthermore, we found that although the current changing environmental conditions in Africa affect the habitats of these freshwater organisms, current changing environmental conditions may not be suppressing the population distributions or abundance of these freshwater organisms. Instead, we found that these freshwater organisms are extending their geographic ranges across Africa, which may have significant public health implications in Africa. Thus, our study demonstrates the need for future studies to integrate the environmental conditions of vectors' habitats to understand if these environmental conditions directly or indirectly influence the vectorial capacities and transmission abilities of vectors of diseases. We propose that such studies will be necessary to guide policymakers in making informed policies to help control vector-borne diseases.

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RESUMEN

Microplastic pollution is a ubiquitous and emerging environmental and public health concern in Africa due to increased plastic production, product and waste importation, and usage. While studies on the environmental monitoring and characterization of microplastics demonstrated the urgent need for a drastic reduction in plastic waste generation, the effectiveness of the various regulatory and policy interventions implemented or proposed in Africa countries remains poorly understood. We critically examined policies, legislations, and regulations enacted to control microplastic pollution in Africa to develop a sustainable, harmonized framework for the coordinated reduction of plastic waste generation across Africa. Analysis of the interventions revealed most African countries employed traditional perspective (i.e., command-and-control) approaches, whereby state instruments such as plastic ban, production and importation levies, and consumer taxes were enacted. However, the continued increase in microplastic waste generation suggests traditional perspective approaches might not be effective in Africa. Although rarely used in Africa, market-oriented approaches such as private-public waste management are often effective in controlling plastic pollution. Hence, we proposed a bottom-up hybrid regulatory approach for managing microplastics pollution in Africa, involving price-based, right-base, legislation and behavioral frameworks based on best practices in microplastic waste management.

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