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Thompson, T. Q.

Publications and source records attributed to Thompson, T. Q..

2 recordsLinked to original sources

Every cog and wheel: Unraveling biocomplexity at the genomic and phenotypic level in a population complex of Chinook salmon.

Genomic diversity is the fundamental building block of biodiversity and the necessary ingredient for adaptation. Our rapidly increasing ability to quantify functional, compositional, and structural genomic diversity of populations forces the question of how to balance conservation goals - should the focus be on important functional diversity and key life history traits or on maximizing genomic diversity as a whole? Specifically, the intra-specific diversity (biocomplexity) comprised of phenotypic and genetic variation can determine the ability of a population to respond to changing environmental conditions. Here, we explore the biocomplexity of Californias Central Valley Chinook salmon (Oncorhynchus tshawytscha) population complex at the genomic level. Notably, despite apparent gene flow among individuals with the same migration (life history) phenotypes inhabiting different tributaries, each group is characterized by a surprising component of unique genomic diversity. Our results emphasize the importance of formulating conservation goals focused on maintaining biocomplexity at both the phenotypic and genotypic level. Doing so will maintain the species adaptive potential and increase the probability of persistence of the population complex despite changing environmental pressures.

ecology↗

Anthropogenic habitat alteration leads to rapid loss of adaptive variation and restoration potential in wild salmon populations

Phenotypic variation is critical for the long-term persistence of species and populations. Anthropogenic activities have caused substantial shifts and reductions in phenotypic variation across diverse taxa, but the underlying mechanism (i.e., phenotypic plasticity and/or genetic evolution) and potential to recover previous phenotypic characteristics are unclear. Here we investigate changes in adult migration characteristics of wild salmon populations caused by dam construction and other anthropogenic habitat modifications. Strikingly, we find that dramatic allele frequency change (i.e., genetic evolution) from strong selection at a single locus explains the rapid phenotypic shift observed after recent dam construction. Furthermore, ancient DNA analysis confirms the abundance of a specific allele associated with adult migration type in historical habitat that will soon become accessible through a large restoration (i.e., dam removal) project. However, analysis of contemporary samples suggests the restoration will be challenged by loss of the allele from potential source populations. These results highlight the need to conserve and restore critical adaptive variation before the potential for recovery is lost.

genetics↗