Speciation genomics for the study of non-adaptative radiations: the case of cryptic lineage divergence in West European voles

Funding: French ministry of research grant

Supervisors: Sophie Montuire and Aurélie Khimoun

Started in october 2025

Abstract

Global climate change represents a major threat to current biodiversity, and studying species’ responses to past climate changes can help predict their response to current changes. The climatic oscillations of the Quaternary had a significant impact on species diversification. Some species, particularly small mammals, experienced rapid and often cryptic diversifications (i.e., without obvious phenotypic changes). These diversifications, known as non-adaptive radiations, did not lead to adaptation to specific niches but resulted in generally allopatric species occupying similar niches. The genus Microtus, a rodent widely distributed across Eurasia, is a good model for studying the impact of climate changes on population divergence and speciation. This genus, which includes more than 65 species complexes, shows a high species richness inherited from glacial cycles. Among the studied species, Microtus agrestis, M. lavernedii, and M. rozianus, defined as sister species, exhibit secondary contact zones, providing an opportunity to study the mechanisms of divergence. The thesis project has three main objectives. The first is to delimit the geographic boundaries of the species and their contact zones using mitochondrial DNA sequence data. The second objective is to explore the demographic histories of populations, using whole genomes to understand colonization dynamics and the effects of glacial cycles. Finally, the third objective focuses on secondary contacts between M. agrestis and M. lavernedii, studying the genomic consequences of hybridization, particularly regarding introgression and the emergence of cryptic lineages. This research aims to shed light on the role of gene flow in the emergence and maintenance of cryptic lineages, as well as on the genomic architecture of speciation.

Keywords

speciation, hybridization, genomics, vole

extrait:

lien_externe:

titre:

Génomique de la spéciation pour l’étude des radiations non-adaptatives: le cas de la divergence de lignées cryptiques chez les campagnols ouest-européens

date_de_debut_these:

octobre 2025

nom:

Camizuli

date_de_debut_these_numerique:

20251001

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kc_raw_content:

Speciation genomics for the study of non-adaptative radiations: the case of cryptic lineage divergence in West European voles

Funding: French ministry of research grant

Supervisors: Sophie Montuire and Aurélie Khimoun

Started in october 2025

 

Abstract

Global climate change represents a major threat to current biodiversity, and studying species' responses to past climate changes can help predict their response to current changes. The climatic oscillations of the Quaternary had a significant impact on species diversification. Some species, particularly small mammals, experienced rapid and often cryptic diversifications (i.e., without obvious phenotypic changes). These diversifications, known as non-adaptive radiations, did not lead to adaptation to specific niches but resulted in generally allopatric species occupying similar niches. The genus Microtus, a rodent widely distributed across Eurasia, is a good model for studying the impact of climate changes on population divergence and speciation. This genus, which includes more than 65 species complexes, shows a high species richness inherited from glacial cycles. Among the studied species, Microtus agrestis, M. lavernedii, and M. rozianus, defined as sister species, exhibit secondary contact zones, providing an opportunity to study the mechanisms of divergence. The thesis project has three main objectives. The first is to delimit the geographic boundaries of the species and their contact zones using mitochondrial DNA sequence data. The second objective is to explore the demographic histories of populations, using whole genomes to understand colonization dynamics and the effects of glacial cycles. Finally, the third objective focuses on secondary contacts between M. agrestis and M. lavernedii, studying the genomic consequences of hybridization, particularly regarding introgression and the emergence of cryptic lineages. This research aims to shed light on the role of gene flow in the emergence and maintenance of cryptic lineages, as well as on the genomic architecture of speciation.

Keywords

speciation, hybridization, genomics, vole