Coupling demographic and genetic variability from archived collections of European anchovy (Engraulis encrasicolus).

It is well known that temporal fluctuations in small populations deeply influence evolutionary potential. Less well known is whether fluctuations can influence the evolutionary potentials of species with large census sizes. Here, we estimated genetic population parameters from as survey of polymorphic microsatellite DNA loci in archived otoliths from Adriatic European anchovy (Engraulis encrasicolus), a fish with large census sizes that supports numerous local fisheries. Stocks have fluctuated greatly over the past few decades, and the Adriatic fishery collapsed in 1987. Our results show a significant reduction of mean genetic parameters as a consequence of the population collapse. In addition, estimates of effective population size (Ne) are much smaller than those expected in a fishes with large population census sizes (Nc). Estimates of Ne indicate low effective population sizes, even before the population collapse. The ratio Ne/Ne ranged between 10−6 and 10−8, indicating a large disc...

众所周知，小型种群的时序波动会深刻影响其进化潜能。然而目前尚无定论：这类波动是否会对普查种群规模庞大的物种的进化潜能产生影响。本研究以亚得里亚海欧洲鳀（Engraulis encrasicolus）为研究对象，通过对其归档耳石（otoliths）中的多态微卫星DNA（microsatellite DNA）位点进行分析，估算其种群遗传参数；该鱼种普查规模庞大，支撑了诸多地方渔业产业。过去数十年间，其种群数量波动剧烈，亚得里亚海该渔业于1987年发生崩溃。研究结果显示，种群崩溃导致其平均遗传参数出现显著下降。此外，有效种群大小（effective population size, Ne）的估算值远低于普查规模庞大的鱼类的预期水平。Ne的估算结果表明，即便在种群崩溃发生之前，其有效种群规模已然偏低。Ne与Ne的比值介于10^-6至10^-8之间，表明存在大规模的