The Norwegian lemming (Lemmus lemmus) is a small rodent distributed across the Fennoscandian mountain tundra and the Kola Peninsula. The Norwegian lemming likely evolved during the Late Pleistocene and inhabited Fennoscandia shortly prior to the Last Glacial Maximum. However, the exact timing and origins of the species, and its phylogenetic position relative to the closely related Siberian lemming (Lemmus sibiricus) remain disputed. Moreover, the presence of ancient or contemporary gene flow between both species is largely untested. The Norwegian lemming displays characteristic phenotypic and behavioral adaptations (e.g., coat color, aggression) that are not present in other Lemmus species. We generated a de novo genome assembly for the Norwegian lemming and resequenced nine modern and two ancient Lemmus spp. genomes. We show that all Lemmus species form distinct monophyletic clades, with concordant topology between the mitochondrial and nuclear genome phylogenies. The Siberian lemming is divided into two distinct but paraphyletic clades, one in the east and one in the west, where the western clade represents a sister taxon to the Norwegian lemming. We estimate that the Norwegian and western Siberian lemming diverged shortly before the Last Glacial Maximum, making the Norwegian lemming one of the youngest known mammalian species. We did not find any indication of gene flow between L. lemmus and L. sibiricus, suggesting postglacial isolation of L. lemmus. Furthermore, we identify species-specific genomic differences in genes related to coat color and fat transport, which are likely associated with the distinctive coloration and overwintering behavior observed in the Norwegian lemming.
Located in
Library
/
RBINS Staff Publications 2025
Geothermal energy is progressively gaining ground in Belgium, with tailored strategies emerging across its three Regions. Wallonia has undertaken a comprehensive modernization of its regulatory instruments, set ambitious renewable heat targets, and initiated large-scale subsurface exploration. Flanders is reinforcing its leadership in deep geothermal by targeting new geological formations, while improving shallow geothermal integration and subsurface governance. In the Brussels-Capital Region, efforts focus on incorporating shallow geothermal into urban energy planning through spatial zoning, technical potential mapping, and system monitoring. A suite of regional and European research projects (e.g. GEOCAMB, DESIGNATE, MORE-GEO, URGENT) have played a pivotal role in de-risking geothermal development by providing interdisciplinary tools that address geological complexity, economic feasibility, and environmental performance. Nevertheless, geothermal energy accounted for only 3.3% of Belgium’s renewable heat production in 2023, highlighting the need for accelerated deployment - especially in deep systems. Achieving carbon neutrality by 2050 will require stronger political commitment, harmonized regulatory frameworks, and targeted financial incentives. Ongoing pilot projects and scientific advances confirm geothermal energy's potential to become a cornerstone of Belgium’s sustainable heating transition.
Located in
Library
/
RBINS Staff Publications 2025
