BEIJING, China — Marmots represent one of the most prominent fossorial mammal taxa inhabiting the grasslands and alpine meadows of the Northern Hemisphere. Nevertheless, their geographic origin, continental dispersal routes, and the environmental drivers underlying their evolutionary history have remained longstanding unresolved questions.
A new study integrating fossil, distributional and molecular evidence traces the evolutionary history of marmots back to North America and reveals how geological and climatic changes drove their dispersal and diversification. Published in Journal of Systematics and Evolution , the study was led by researchers from the Institute of Zoology, Chinese Academy of Sciences, in collaboration with Xinjiang University, Shenyang Agricultural University and institutions in Russian Academy of Sciences.
“Marmots are now widely distributed across North America and Eurasia, but their modern distribution alone cannot reveal where they originated or how they reached different continents,” said Qiujin Wei, lead author of the study. “By combining fossil records with molecular phylogeny and ancestral range reconstruction, we were able to build a more complete picture of their evolutionary history.”
The researchers compiled 965 reliably identified marmot fossil records and 155,603 occurrence records for living species. They also sequenced 19 tissue samples and combined them with publicly available data to analyze all 13 mitochondrial protein-coding genes from 58 individuals.
The earliest known marmot fossil was discovered in North America and dates to approximately 16.3 million years ago. Bayesian ancestral-range reconstruction, considered together with the fossil evidence, identifies North America as the most likely cradle of the genus. Molecular-clock analysis further indicates that the diversification of extant marmots commenced around 6.09 million years ago, which was followed by their divergence into the subgenera Marmota and Petromarmota .
Crossing continents through Beringia
The reconstructed history revealed four major intercontinental dispersal events: two from North America to Asia, one from North America to Europe and one from Asia to Europe. These findings identify the Bering Land Bridge as a crucial evolutionary corridor connecting North America and Eurasia.
“The Bering region was not simply a geographic bridge, it repeatedly provided marmots with opportunities to enter new environments and expand their ranges,” said Deyan Ge, corresponding author of the study. “These dispersal events played a central role in establishing the modern distribution of the genus.”
After reaching Eurasia, marmots expanded westward into Europe and diversified across the mountain systems, steppes and alpine meadows of Central and northern Asia.
Climate and mountains shaped diversification
Fossil and molecular evidence indicates that marmot evolution was closely associated with changes in climate, vegetation and topography. Relatively high speciation during the Late Miocene and Pliocene coincided with global cooling, the expansion of C 4 grasslands and the emergence of the Bering Land Bridge. Subsequent mountain uplift created geographic barriers that promoted regional adaptation and allopatric speciation.
Around one million years ago, speciation and extinction rates increased simultaneously, resulting in only a modest rise in net diversification. The researchers associate this shift with strong Pleistocene glacial–interglacial oscillations, which repeatedly fragmented marmot habitats while also creating opportunities for isolated populations to diverge.
“Our results show that marmot diversity was shaped by the interaction of dispersal, climate change and mountain building,” said Qiujin Wei. “Environmental change both opened new routes for expansion and isolated populations, producing the evolutionary patterns observed today.”
Original Source:
Qiujin Wei, Ning Liu, Lei Cao, Xinkun Kang, Alexei Abramov, Biao Duan, Andrey Lissovsky, Xiaohu Han, Wenjuan Shan, and Deyan Ge. 2026. "Unraveling the origins, dispersal patterns, and evolutionary trajectory of marmots through integrated fossil and molecular evidence." Journal of Systematics and Evolution.
https://doi.org/10.1111/jse.70105
Keywords:
fossil record, historical biogeography, Marmota , molecular clock, net diversification rate
Author’s Institution ( voluntary ):
The Key Laboratory of Animal Biodiversity Conservation and Integrated Pest Management, Institute of Zoology, Chinese Academy of Sciences (CAS), constitutes a premier research unit with a core focus on animal diversity conservation, pest management, and evolutionary biology. The Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, at Xinjiang University, serves as a prominent regional research center dedicated to the conservation, research, and exploitation of biological resources unique to Xinjiang. The present study further incorporated collaborating institutions in China and Russia, each possessing substantial expertise in mammalian ecology, biogeography, and evolution.
About JSE:
Journal of Systematics and Evolution (JSE) is a peer-reviewed, bi-monthly international English-language journal dedicated to the understanding of biodiversity and evolution. Papers in any of the following and related fields will be considered: systematics and biodiversity conservation, paleobiology and biogeography, adaptation, speciation and domestication, evolutionary genomics and Evo-Devo, theory and methods in evolutionary biology.
Journal of Systematics and Evolution
Unraveling the origins, dispersal patterns, and evolutionary trajectory of marmots through integrated fossil and molecular evidence
31-Aug-2026