Publications by authors named "J Brian Dempson"
Complex traits often exhibit complex underlying genetic architectures resulting from a combination of evolution from standing variation, hard and soft sweeps, and alleles of varying effect size. Increasingly, studies implicate both large-effect loci and polygenic patterns underpinning adaptation, but the extent that common genetic architectures are utilized during repeated adaptation is not well understood. Sea age or age at maturation represents a significant life history trait in Atlantic Salmon (), the genetic basis of which has been studied extensively in European Atlantic populations, with repeated identification of large-effect loci.
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- Gene flow between wild and domestic salmon populations is a significant concern, particularly regarding the influence of European salmon on North American aquaculture despite regulations against their use in Canada.
- Evidence shows that farmed salmon in North America increasingly exhibit European ancestry, with some individuals having over 40% European genetic material.
- Studies reveal that even juvenile wild salmon near aquaculture sites show signs of European heritage, indicating that hybridization and the potential impacts on wild populations are ongoing issues.
Article Synopsis
- The study examines how Arctic Charr adapted to deep-water environments after the last ice age, focusing on genetic differences between deep-water and shallower morphs.
- It highlights significant genomic divergence, with different genetic regions related to gene expression, DNA repair, cardiac function, and membrane transport adapting to the distinct challenges of deep waters.
- The findings indicate recent morph divergence and reduced genetic diversity, underscoring the evolutionary processes at play in adapting to extreme aquatic habitats in the wake of postglacial colonization.
Domestication is rife with episodes of interbreeding between cultured and wild populations, potentially challenging adaptive variation in the wild. In Atlantic salmon, , the number of domesticated individuals far exceeds wild individuals, and escape events occur regularly, yet evidence of the magnitude and geographic scale of interbreeding resulting from individual escape events is lacking. We screened juvenile Atlantic salmon using 95 single nucleotide polymorphisms following a single, large aquaculture escape in the Northwest Atlantic and report the landscape-scale detection of hybrid and feral salmon (27.
View Article and Find Full Text PDFBody-element content was measured for three life stages of wild Atlantic salmon Salmo salar from three distinct Newfoundland populations as individuals crossed between freshwater and marine ecosystems. Life stage explained most of the variation in observed body-element concentration whereas river of capture explained very little variation. Element composition of downstream migrating post-spawn adults (i.
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