Phylogenetic Dynamics and Biogeography of North American Rodents

North American rodents exhibit a rich evolutionary tapestry shaped by climatic oscillations, geological events and complex dispersal routes. Patterns of speciation and lineage diversification have been driven by Pleistocene glaciations, mountain uplifts and the formation of refugial landscapes, resulting in high endemism across regions such as the Sierra Nevada, the Great Plains and the Pacific Northwest. Advances in molecular systematics have yielded time-calibrated phylogenies that resolve deep splits among arvicoline voles, ground squirrels and pocket gophers, while genome-scale data illuminate recent radiations in deer mice and woodrats. Biogeographic reconstructions reveal repeated northward expansions via Beringia, southward retreats during glacial maxima and instances of secondary contact leading to hybrid zones along coastal and montane barriers. Comparative analyses underscore the interplay between habitat specialisation and dispersal capacity, with generalists often showing broader distributions yet lower speciation rates than biome specialists. Integration of host–parasite co-evolutionary frameworks further highlights how biotic interactions have shaped rodent diversification and contemporary range limits. This synthesis underscores the global significance of North American rodent systems for understanding evolutionary processes under past and future environmental change.

Research from Nature Portfolio

Recent studies employing ancient DNA from Late Pleistocene specimens of arctic ground squirrels have revised long-standing taxonomic assignments, demonstrating mitochondrial continuity between ancient lineages and modern populations across Beringia. These findings clarify dispersal dynamics during glacial–interglacial cycles and reject hypotheses of distinct extinct species in western Beringia. Such work exemplifies the power of full mitochondrial genome sequencing to resolve deep phylogenetic splits and to reconstruct post-glacial colonisation pathways into North America.

Phylogenetic Dynamics and Biogeography of North American Rodents publication trend

The graph below shows the total number of articles in phylogenetic dynamics and biogeography of north american rodents across all publications each year (not limited to Nature Index journals).

Technical terms

Phylogenetic reconstruction: Inference of evolutionary relationships among species based on genetic or morphological data.

Mitochondrial DNA: The maternally inherited genome found in cell mitochondria, commonly used to trace lineage history and population structure.

Coalescent analysis: A statistical framework modelling genealogical relationships to estimate divergence times and past population dynamics.

Vicariance: The geographical separation of a population by physical barriers, leading to genetic divergence and speciation.

Introgression: The incorporation of genetic material from one lineage into another through hybridisation and backcrossing.

Lineage sorting: The process by which genetic variants become fixed or lost in diverging populations over time.

References

1. DNA analysis of a 30,000-year-old Urocitellus glacialis from northeastern Siberia reveals phylogenetic relationships between ancient and present-day arctic ground squirrels. Scientific Reports (2017).
2. The Beringian Coevolution Project: holistic collections of mammals and associated parasites reveal novel perspectives on evolutionary and environmental change in the North1. Arctic Science (2016).
3. Diversification of the Alpine Chipmunk, Tamias alpinus,an alpine endemic of the Sierra Nevada, California. BMC Ecology and Evolution (2014).
4. Historic hybridization and persistence of a novel mito-nuclear combination in red-backed voles (genus Myodes). BMC Ecology and Evolution (2009).