Evidence for fisheries induced evolution at the genome level in a heavily exploited fish stock, the Eastern Baltic cod (Gadus morhua)
Human driven perturbations, including overfishing, are one of the greatest evolutionary forces within marine ecosystems. Overharvesting of wild populations is often highly selective for particular traits and elicits the strongest phenotypic changes, while the evolutionary basis of such trait change is mostly unresolved. Here, we use whole genome sequencing with a unique temporal dataset from the overexploited Eastern Baltic cod (Gadus morhua), to investigate the genomic causes and consequences of a 48% decrease in asymptotic body length over the last 25 years. Genome-wide association analyses revealed pronounced outlier gene candidates linked to growth performance. The contributing loci showed signals of directional selection with significantly high autocovariance in allele frequency change and marked intersections with regions of high Fst genes relevant to growth and reproduction. Moreover, pattern of directional selection for the ancestral haplotype of the well-known chromosomal inversions in Atlantic cod (on linkage group 12) was observed, while the double crossover (~1Mb) containing the vitellogenin genes within this region showed signs of drift or balancing selection. Our results identify the genomic basis of fisheries driven body size reduction in Eastern Baltic cod over only 25 years and underscore implications for fisheries management and conservation policy regarding the adaptive potential of marine populations.
Vorschau
Rechte
Nutzung und Vervielfältigung:
Bitte beachten Sie, dass einzelne Bestandteile der Publikation anderweitigen Lizenz- bzw. urheberrechtlichen Bedingungen unterliegen können.