Department of Biology, Dalhousie University, 1355 Oxford St, Halifax, Nova Scotia B3H4R2, Canada.
Pacific Biological Station, Nanaimo, Canada.
J Theor Biol. 2018 Nov 7;456:279-294. doi: 10.1016/j.jtbi.2018.08.015. Epub 2018 Aug 10.
Culturally-transmitted ecological specialization occurs in killer whales, as well as other species. We hypothesize that some of the remarkable demographic and ecological attributes of killer whales result from this process. We formalize and model (using agent-based stochastic models parametrized using killer whale life history) the cultural evolution of specialization by social groups, in which a narrowing of niche breadth is spread and maintained in a group through social learning. We compare the demographic and ecological results of cultural specialization to those of a similar model of specialization through natural selection. We found that specialization, through either the cultural or natural selection routes, is adaptive in the short term with specialization often increasing fitness. Generalization, in contrast, is rarely adaptive. The cultural evolution of specialization can lead to increased rates of group extirpation. Specialization has little effect on group size but tends to reduce population size and resource abundance. While the two specialization processes produce similar results, cultural specialization can be very much faster. The results are generally consistent with what we know of the formation and maintenance of specialist ecotypes in killer whales, and have implications for the persistence, nature and ecological effects of these apex predators.
文化传递的生态特化也发生在虎鲸等物种中。我们假设，虎鲸一些显著的种群和生态特征正是由这一过程导致的。我们通过基于主体的随机模型（使用虎鲸生活史参数化）形式化和模拟了通过社会学习在群体中传播和维持生态特化的文化进化过程。我们将文化特化和通过自然选择的特化的种群和生态结果进行了比较。我们发现，无论是通过文化还是自然选择的特化，在短期内都是适应性的，特化往往会增加适应性。相反，泛化很少是适应性的。通过文化进化的特化可能导致群体灭绝率的增加。特化对群体大小几乎没有影响，但往往会减少种群数量和资源丰度。虽然这两个特化过程产生了相似的结果，但文化特化的速度要快得多。这些结果与我们对虎鲸中形成和维持特化生态型的了解基本一致，对这些顶级捕食者的持续存在、性质和生态影响具有重要意义。
