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The article focuses on the critical role of Mexico's National Commission for the Knowledge and Use of Biodiversity (CONABIO) in safeguarding biodiversity, emphasizing its imminent threat due to proposed governmental restructuring. Topics discussed include the pivotal functions of CONABIO in biodiversity research, management, and policy guidance, highlighting its potential demise's detrimental impact on global biodiversity conservation efforts.

Since it was defined by Hutchinson, in 1957, the fundamental niche has been assumed, implicitly or explicitly, to have some convex shape. This assumption requires some critical analysis. In this work, we examine the special case of Grinnellian niches (those composed by sets of points of non-interactive variables in multidimensional spaces). We show that annual species in seasonal environments are likely to have very non-convex shapes, and be composed not of sets of points, but of sets of trajectories. We also examine under what circumstances trajectories may be approximated using sets of points. It appears to be the case that the breadth of requirements at each stage in the life history is a key parameter. We conclude by comparing the situation with perennial species. [ABSTRACT FROM AUTHOR]

Aim: Assessing the relevance of niche evolution in the diversification patterns and geographical distribution of species driven by climate remains a challenge. We apply an integrative approach to evaluate the role of the environment on the phylogeography of bear species, incorporating fossil data to characterize the changes in the ecological niche through time. We evaluate our approach with the four extant species of bears within Ursus, the best represented taxon in the fossil record of the family Ursidae. Location: Eurasia and North America. Taxa: Asian black bear, Ursus thibetanus; American black bear, U. americanus; Brown bear, U. arctos; and Polar bear, U. maritimus. Methods: We built a genetic and a geographical database from all published mitochondrial DNA sequences and of species occurrence records. We defined the most significant climatic variables based on each species ecological realm using correlation matrices, and characterized the ecological niches and existing environmental conditions with ellipsoid models. We inferred their current and Last Glacial Maximum (LGM) ecological niche modellings (ENMs) and compared the results with the fossil record. We estimated the times of divergence (d‐loop sequences) of lineages and applied a phyloclimatespace approach to discern the phylogeographical patterns along each species' ecological space. Results: Ecological niche modelling showed wider niches for U. thibetanus and U. americanus encompassing higher temperature and precipitation, while U. arctos and U. maritimus showed an opposite pattern. LGM models were consistent with the fossil record, predicting 55%–89% of the fossil occurrences (within their suitability areas). The phyloclimatespace revealed different degrees of environmental signal in the lineages' phylogeographical patterns and ecological trajectories associated with LGM climatic conditions. Results indicated habitat tracking and ecological expansion since the LGM towards more extreme precipitation and temperature conditions for three species, except U. maritimus that showed ecological niche reduction. Main Conclusions: Incorporating fossil information from the LGM improved our characterization and interpretation of ecological models, by enabling definition of the limits of the climatic conditions explored by the species in the past. Our approach also provided insights about the existing set of environmental conditions shaping the ecological niche divergence of Ursus bears. We were able to depict key features of the lineages' evolutionary history, ecology and distribution, revealing the dynamics of niche occupation and the environmental signal on the phylogeographical patterns of Ursus. [ABSTRACT FROM AUTHOR]