The article discusses the importance of rear edge populations in the conservation of biodiversity under climate change. It argues that these populations, located at the low-latitude margins of species' ranges, are often disproportionately important for the survival and evolution of biota. Unlike the expanding edge, rear edge populations have been understudied, and their conservation needs differ from those of populations in other parts of the range. The paper reviews recent findings from the fossil record, phylogeography, and ecology to illustrate that rear edge populations are often disproportionately important for the survival and evolution of biota. Their ecological features, dynamics, and conservation requirements differ from those of populations in other parts of the range, and some commonly recommended conservation practices might therefore be of little use or even counterproductive for rear edge populations. The paper also discusses the long-term importance of the rear edge, highlighting its role in the diversification of the biota and the maintenance of biodiversity throughout the Quaternary. It emphasizes the need for further research and conservation measures to address the unique challenges faced by rear edge populations. The paper concludes that current conservation strategies may not be sufficient to protect these populations, and that more research is needed to develop appropriate conservation strategies that take into account the peculiarities of rear edge populations.The article discusses the importance of rear edge populations in the conservation of biodiversity under climate change. It argues that these populations, located at the low-latitude margins of species' ranges, are often disproportionately important for the survival and evolution of biota. Unlike the expanding edge, rear edge populations have been understudied, and their conservation needs differ from those of populations in other parts of the range. The paper reviews recent findings from the fossil record, phylogeography, and ecology to illustrate that rear edge populations are often disproportionately important for the survival and evolution of biota. Their ecological features, dynamics, and conservation requirements differ from those of populations in other parts of the range, and some commonly recommended conservation practices might therefore be of little use or even counterproductive for rear edge populations. The paper also discusses the long-term importance of the rear edge, highlighting its role in the diversification of the biota and the maintenance of biodiversity throughout the Quaternary. It emphasizes the need for further research and conservation measures to address the unique challenges faced by rear edge populations. The paper concludes that current conservation strategies may not be sufficient to protect these populations, and that more research is needed to develop appropriate conservation strategies that take into account the peculiarities of rear edge populations.