Phylogeography and Genetic Diversity of Salmonid Fishes

Salmonid fishes, encompassing salmon, trout and chars, exhibit a complex history shaped by Pleistocene glaciations, post-glacial colonisation and contemporary riverine dynamics. Phylogeography combines molecular data with palaeoenvironmental reconstructions to trace lineage splits, dispersal corridors and secondary contact zones. These studies reveal that glacial refugia in southern Europe, North America and Beringia served as sanctuaries for distinct clades, which later radiated into deglaciated watersheds. Genetic diversity within and between populations is influenced by historical bottlenecks, gene flow across watersheds and local adaptation to temperature, flow regime and spawning habitat. Contemporary pressures—habitat fragmentation, climate change and aquaculture escapees—further modulate diversity and may erode locally adapted gene pools. Conserving evolutionary potential therefore requires recognition of cryptic lineages, management units below the species level and the interplay between neutral variation and adaptive traits. Advances in high-throughput sequencing now enable fine-scale reconstruction of colonisation routes, the detection of adaptive genomic regions and predictive models of resilience under changing environmental scenarios.

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Phylogeography and Genetic Diversity of Salmonid Fishes publication trend

The graph below shows the total number of articles in phylogeography and genetic diversity of salmonid fishes across all publications each year (not limited to Nature Index journals).

Technical terms

Phylogeography: The study of the geographical distribution of genetic lineages within and among closely related populations.

Haplotype: A set of DNA variations inherited together that can trace maternal or paternal lineages.

Lineage: A sequence of populations or species connected by ancestral descent.

Glacial refugium: A geographically restricted area where populations survived during glacial maxima.

Admixture: The interbreeding of distinct genetic groups leading to mixed ancestry.

Population structure: The organisation of genetic variation into discrete or clinal groups due to historical and contemporary barriers to gene flow.

References

1. Biogeography of Beringian fishes after the molecular revolution and into the post-genomics era. Reviews in Fish Biology and Fisheries (2024).
2. Historical and contemporary processes driving the origin and structure of an admixed population within a contact zone between subspecies of a north temperate diadromous fish. Molecular Ecology (2024).
3. Phylogeny, Distribution, and Biology of Pygmy Whitefish (Prosopium coulterii) in the Beringia Region (Chukotka). Diversity (2023).