Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, UK.
Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, UK; Centre for Research in Ecology, Evolution and Behaviour, University of Roehampton, London SW15 4JD, UK.
Curr Biol. 2018 Jun 4;28(11):1846-1850.e2. doi: 10.1016/j.cub.2018.05.001. Epub 2018 May 24.
Cultural inheritance, the transmission of socially learned information across generations, is a non-genetic, "second inheritance system" capable of shaping phenotypic variation in humans and many non-human animals [1-3]. Studies of wild animals show that conformity [4, 5] and biases toward copying particular individuals [6, 7] can result in the rapid spread of culturally transmitted behavioral traits and a consequent increase in behavioral homogeneity within groups and populations [8, 9]. These findings support classic models of cultural evolution [10, 11], which predict that many-to-one or one-to-many transmission erodes within-group variance in culturally inherited traits. However, classic theory [10, 11] also predicts that within-group heterogeneity is preserved when offspring each learn from an exclusive role model. We tested this prediction in a wild mammal, the banded mongoose (Mungos mungo), in which offspring are reared by specific adult carers that are not their parents, providing an opportunity to disentangle genetic and cultural inheritance of behavior. We show using stable isotope analysis that young mongooses inherit their adult foraging niche from cultural role models, not from their genetic parents. As predicted by theory, one-to-one cultural transmission prevented blending inheritance and allowed the stable coexistence of distinct behavioral traditions within the same social groups. Our results confirm that cultural inheritance via role models can promote rather than erode behavioral heterogeneity in natural populations.
文化传承是指社会习得信息在世代间的传递，它是非遗传的“第二遗传系统”，能够塑造人类和许多非人类动物的表型变异[1-3]。对野生动物的研究表明，一致性[4,5]和对特定个体的模仿倾向[6,7]可以导致文化传播行为特征的快速传播，并导致群体内和群体间的行为同质性增加[8,9]。这些发现支持了经典的文化进化模型[10,11]，该模型预测，多对一或一对多的传播会削弱文化遗传特征的群体内变异性。然而，经典理论[10,11]还预测，当后代从独特的角色模型中学习时，群体内的异质性会得到保留。我们在一种野生哺乳动物——条纹獴（Mungos mungo）中检验了这一预测，在这种哺乳动物中，幼崽由特定的成年照顾者抚养，而不是它们的亲生父母，这为我们提供了一个机会来区分行为的遗传和文化传承。我们通过稳定同位素分析表明，年轻的獴从文化角色模型而不是从遗传父母那里继承成年觅食生态位。正如理论所预测的那样，一对一的文化传播阻止了混合遗传，并允许在同一社会群体中稳定共存不同的行为传统。我们的结果证实，通过角色模型进行文化传承可以促进而不是削弱自然种群中的行为异质性。
