Cultural flies: conformist social learning in fruit flies predicts long-lasting mate-choice traditions

Despite theoretical justification for the evolution of animal culture, there is still scant empirical evidence for it beyond mammals and birds, and we still know little about the process of cultural inheritance. Here, we propose a mechanism-driven definition of animal culture and test it in the fruit fly. We found that fruit flies have five cognitive capacities that enable them to transmit mating preferences culturally across generations, potentially fostering persistent traditions (the main marker of culture) in mating preference. A transmission chain experiment validates a model of the emergence of local traditions indicating that such social transmission may lead initially neutral traits to become adaptive, hence strongly selecting for copying and conformity, a situation that, although suggested decades ago, still had little empirical support.

尽管动物文化演化具备理论支撑，但目前除哺乳类与鸟类外，相关实证证据仍较为匮乏，且我们对文化传承的具体过程仍知之甚少。本研究提出了一种机制驱动型的动物文化定义，并以果蝇为对象进行了验证。研究发现，果蝇具备五项认知能力，使其能够跨代以文化路径传递择偶偏好，或可催生择偶偏好领域的持续性传统——这正是文化的核心标志之一。本研究通过传递链实验验证了地方性传统涌现的理论模型，结果显示这类社会传递可使原本中性的性状逐渐获得适应性，进而强烈选择出模仿与从众行为；尽管这一观点在数十年前便已被提出，但至今仍缺乏充足的实证支撑。