Throwing down a genomic gauntlet on fisheries-induced evolution.

Beginning with studies on crypsis and camouflage, the hypothesis that predators can generate evolutionary change in their prey has a long and rich history (1). Few predators, however, rival humans in their potential to generate selection responses and concomitant phenotypic change on contemporary timescales. In the 1930s, J. B. S. Haldane (2) mused that fishing would be an ideal candidate for such “observable evolution” within a human lifetime, proceeding “with extreme and abnormal speed.” However, it was not until the late 1970s that research on fisheries-induced evolution (FIE) gained a substantive scientific foothold, beginning with thought-provoking work on Canadian whitefish ( Coregonus clupeaformis ) (3) and Pacific salmon ( Oncorhynchus spp.) (4). Backed by the logical premise that high fishing mortality (selective or not) can generate evolution in heritable traits, a great deal of research on FIE has been empirically fueled by the reductions in age (and often size) at maturity routinely observed in heavily fished natural populations (5). Laboratory studies have repeatedly found that highly intense selection (e.g., 75 to 90% mortality per generation), imposed by age- and size-based culling of obligatorily semelparous experimental populations, can alter life histories and gene frequencies (6⇓–8). These experiments stimulated a slew of mathematical models that have predicted undesirable consequences of FIE—altered life histories, reduced recovery potential, lowered per capita population growth ( r ), decreased sustainable yields—against a backdrop of FIE-induced genetic change that might prove difficult or impossible to reverse (9, 10). Calls for evolutionarily enlightened management have ensued (11, 12). Despite a theoretically strong conceptual basis, evidence of genetic change unequivocally attributable to wild-capture fisheries has been elusive (10, 13). Among the top five threats to biodiversity, evidence for genetic trait change is strongest for studies of pollution and weakest for studies of overexploitation (and habitat change) … [↵][1]1To whom correspondence may be addressed. Email: jhutch{at}dal.ca. [1]: #xref-corresp-1-1