While signals in evolutionary biology are usually defined as “acts or traits that have evolved because of their effect on others”, work on gestures and vocalizations in various animal taxa have revealed population‐ or even individual‐specific meanings of social signals. These results strongly suggest that communicative acts that are like signals with regard to both form and function (meaning) can also be acquired ontogenetically, and we discuss direct evidence for such plasticity in captive settings with rich opportunities for repeated social interactions with the same individuals. Therefore, in addition to evolved signals, we can recognize invented signals that are acquired during ontogeny (either through ontogenetic ritualization or social transmission). Thus, both gestures and vocalizations can be inventions or innate adaptations. We therefore propose to introduce innate versus invented signals as major distinct categories, with invented signals subdivided into dyad‐specific and cultural signals. We suggest that elements of some signals may have mixed origins, and propose criteria to recognize acquired features of signals. We also suggest that invented signals may be most common in species with intentional communication, consistent with their ubiquity in humans, and that the ability to produce them was a necessary condition for the evolution of language.

中文翻译：

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所有信号都必须进化吗？关于对交往行为进行新分类的提案。

虽然进化生物学中的信号通常被定义为“由于对他人的影响而进化出的行为或特征”，但各种动物分类中的手势和发声工作却揭示了社会信号的特定人群甚至特定个体的含义。这些结果有力地表明，也可以从本体论上获得与形式和功能（意义）信号类似的交往行为，并且我们讨论了在圈养环境中这种可塑性的直接证据，这种机会具有与同一个人反复进行社会互动的丰富机会。因此，除了进化的信号外，我们还可以识别在个体发育过程中（通过个体发育的仪式化或社会传播）获得的发明信号。因此，手势和发声都可以是发明或固有的改编。因此，我们建议将先天性信号与发明性信号引入为主要的不同类别，将发明性信号细分为针对二元组的信号和文化信号。我们建议某些信号的元素可能具有混合的起源，并提出标准来识别信号的获取特征。我们还建议，在有意进行交流的物种中，发明信号可能最常见，这与它们在人类中的普遍存在相一致，并且产生信号的能力是语言发展的必要条件。