Does Variance in Breeding Success Limit Effective Population Sizes of Marine Organisms? A Test in a Semi-Isolated Natural Population of Oysters

对于有能力产生大量后代和早期生活阶段高平均死亡率的海洋动物来说，个体将后代贡献给下一代繁殖成虫的成功可能存在很大的差异。对于这些动物来说，后代数量的二项式方差的假设可能是错误的，当繁殖活动和允许的海洋条件不匹配时，一小部分后代可能会在每一代中取代整个种群。为了验证这一假设，华盛顿州达博湾的一个长达30年的繁殖活动和招募成功记录的牡蛎模型种群将通过比较幼体、幼体和成体的遗传多样性进行严格的测试。分子生物学的进步使幼虫种群的遗传多样性研究成为可能。繁殖成功率的巨大差异可能是大多数海洋动物种群生物学、适应和物种形成的一个主要因素。

For marine animals with the capacity of producing large number of offsprings and high average mortalities of early life stages, there exists the potential for a large variance in the success with which individual contribute offspring to the next generation of reproducing adults. For these animals, an assumption of binomial variance in offspring numbers is likely wrong, and that a small minority of offsprings may replace an entire population in each generation when there is a mismatch between reproductive activity and permissive oceanographic conditions. To examine this hypothesis, a model oyster population Crassostrea gigas in Dabob Bay, WA, for which a 30-year record exists on reproductive activity and recruitment success, will be tested rigorously by comparison of genetic diversity among larvae, juveniles, and adults. Genetic diversity studies of larval populations are now made possible by advances in molecular biology. Large variance in reproductive success may be a major factor in the population biology, adaptation and speciation of most marine animals.