Vrba was right: Historical climatic fragmentation, and not current climate, explains mammal biogeography

Climate plays a crucial role in shaping species distribution and evolution over time. Dr. Elisabeth Vrba’s Resource-Use hypothesis posited that zones at the extremes of temperature and precipitation conditions should host a greater number of climate specialist species than other zones because of higher historical fragmentation. Here, we tested this hypothesis by examining climate-induced fragmentation over the past 5 million years. Our findings revealed that, as stated by Vrba, the number of climate specialist species increases with historical regional climate fragmentation, whereas climate generalist species richness decreases. This relationship is approximately 40% stronger than the correlation between current climate and species richness for climate specialist species and 77% stronger for generalist species. These evidences suggest that the effect of climate historical fragmentation is more significant than that of current climate conditions in explaining mammal biogeography. These r..., Climate Data and Classification In this study, we employed the Köppen-Geiger climate classification to categorize climate zones. This system relies on climatic parameters, specifically monthly mean temperature (ºC) and total precipitation (mm), to define climate types (Beck et al., 2018; Köppen, 1884). Given the close correlation between climate and vegetation, these climate zones tend to align closely with global biome patterns (Belda et al., 2014), providing a proxy for examining how climate shapes biome distributions (Mucina, 2019). The Köppen-Geiger climate classification recognises 23 distinct climate regimes, grouped into five major zones: Tropical, Arid, Temperate, Cold, and Polar (Figure 1A). These zones served as the basis for our analysis of the impact of climate change on environmental fragmentation. Climate data for the last 5 million years were obtained from the high-resolution paleoclimate emulator, PALEO-PGEM (Holden et al., 2019). This dataset offers monthly climate info..., , # Data from: Vrba was right: Historical climatic fragmentation, and not current climate, explains mammal biogeography [https://doi.org/10.5061/dryad.x69p8czsn](https://doi.org/10.5061/dryad.x69p8czsn) This dataset includes the information and an R code to run every analysis in the research paper. ## Description of the data and file structure Mammals_db.csv: Database indicating the presence (1) or absence (0) of each mammal species included in this study (N=5739) in each of the pixels that make up the world map at a resolution of 0.5º. Rows correspond to map pixels, while columns correspond to mammal species. The database also contains other information about each pixel such as which landmass and climate zone it belongs to.\ ATTENTION: Large table size, may cause opening issues. Reclassified_maps.zip: Maps displaying the planet's climate reclassified into the 5 main Köppen-Geiger categories on a global scale with a resolution of 0.5º. In TIFF format. Based on the PALEO-PGEM emulato...气候在长期塑造物种分布与演化过程中发挥着至关重要的作用。伊丽莎白·弗巴（Elisabeth Vrba）博士提出的资源利用假说（Resource-Use hypothesis）指出，由于历史上更高程度的气候破碎化，温度与降水条件处于极端区间的生境相较于其他生境，能够承载更多的气候专性物种（climate specialist species）。本研究通过分析过去500万年以来气候驱动的生境破碎化情况，对该假说进行了检验。研究结果正如弗巴所提出的那样：气候专性物种的丰富度随区域历史气候破碎化程度的升高而增加，而气候广适物种（climate generalist species）的丰富度则随之降低。该关联的强度相较于当前气候与气候专性物种丰富度的相关性强约40%，相较于气候广适物种的相关性则强77%。上述结果表明，在解释哺乳动物生物地理学（mammal biogeography）的分布规律时，历史气候破碎化的影响要显著强于当前气候条件。 ## 气候数据与分类 本研究采用柯本-盖格（Köppen-Geiger）气候分类法对气候区进行划分。该系统以气候参数——具体为月平均气温（℃）与总降水量（mm）——为依据定义气候类型（Beck等，2018；柯本，1884）。鉴于气候与植被间存在紧密关联，该气候分类系统的分区与全球生物群系（biome）分布模式高度吻合（Belda等，2014），可为探究气候如何塑造生物群系分布提供代用指标（proxy）（Mucina，2019）。柯本-盖格气候分类法共识别出23种独立气候型，可归为5大气候带：热带、干旱、温带、寒带与极地（图1A）。上述气候带为本研究分析气候变化对环境破碎化的影响提供了基础框架。 过去500万年的气候数据源自高分辨率古气候模拟工具PALEO-PGEM（Holden等，2019）。该数据集提供月尺度气候信息…… 本数据集包含本研究论文中所有分析所需的相关数据与R代码。 ### 数据与文件结构说明 1. **Mammals_db.csv**：本研究共纳入5739种哺乳动物物种，该数据库记录了全球0.5°分辨率地图像素中各物种的存在（1）或缺失（0）情况。数据库行对应地图像素，列对应哺乳动物物种，同时包含各像素所属陆块与气候区等附加信息。 > 注意：该数据表体积较大，打开时可能出现异常。 2. **Reclassified_maps.zip**：该压缩包包含全球0.5°分辨率的重分类气候地图，基于PALEO-PGEM模拟数据制作，将全球气候按柯本-盖格5大气候类别进行划分，格式为TIFF。 [https://doi.org/10.5061/dryad.x69p8czsn](https://doi.org/10.5061/dryad.x69p8czsn)