Conserving biodiversity urgently requires the integration of knowledge across ecological-time, -scales and -disciplines. AA-ungulates will fulfil such major ambition, developing an innovative framework joining palaeoecology to evolutionary demography. By extracting invaluable knowledge from millennia of natural history and detailed demographic data, this project will provide advances in predicting species persistence under rapid global changes. Specifically, the project will study 1) the effect of climate and harvest on effective population sizes of Arctic and Alpine ungulates at historical (using subfossil genomics) and 2) contemporary (using genomics and demography) timescales, to 3) project their population viability under credible climate scenarios. To achieve these novel goals, I propose a pioneering approach linking state-of-the-art genomics from ancient and modern specimens to individual-monitoring programs. To maximize societal impacts, the research focuses on charismatic ungulates sharing histories of hunting-induced bottlenecks and inhabiting biomes warming the fastest on Earth. These unique empirical datasets will allow theoretical advancements by identifying common genetic-to-demography processes, with important insights on how population viability is tied to low genetic diversity. To undertake this integrative endeavor, a two-way transfer of knowledge will be crucial between the Beneficiary (Université Savoie-Mont Blanc, USMB, France) and I. In G. Yannic’s expert group, I will learn about alpine ecology and paleogenomics and in turn will bring knowledge of arctic ecology and demographic biostatistics. A strong collaborative team from 9 institutions in 4 countries, gathering eminent specialists in key aspects of AA-ungulates, will further enrich my network and skills. The high-quality outputs planned, supplemented by the diverse early-career programs at USMB, will give a springboard to become an independent expert in multiscale evolutionary demography.