Research Unit of Biodiversity (CSIC, UO, PA), University of Oviedo, 33071 Oviedo, Spain.
J Anim Ecol. 2012 May;81(3):594-604. doi: 10.1111/j.1365-2656.2011.01946.x. Epub 2012 Jan 19.
1. Antagonistic interactions have been favourite subjects of studies on species co-evolution, because coexistence among competing species often results in quantifiable character displacement. A common output for competitive interactions is trait divergence, although the opposite phenomenon, convergence, has been proposed to evolve in some instances, for example in the communication behaviour of species that maintain mutually exclusive territories. 2. I use here experimental and observational evidence to study how species interactions drive heterospecific signal convergence and analyse how convergence feeds back to the interaction itself, in the form of aggressive behaviour. I recorded the learned territorial signals of two non-hybridizing larks, Galerida cristata and G. theklae, and used allopatric populations as controls for evaluating acoustic convergence in syntopy. Acoustic variation was analysed with respect to social conditions controlling for other potential agents of natural selection, habitat and climate. 3. Interspecific convergence of Galerida calls peaked in syntopy. Although call acoustic structure was affected by climate and habitat, it matched gradients of density and proximity to congeners even at small local scales. The process of cultural transmission, in which individuals may acquire components of behaviour by copying neighbours, enhances the correlation between call acoustics and the local social milieu. 4. Territories were defended against both species, but playback stimuli of convergent congener calls elicited a stronger aggressive reaction than congener calls from allopatric locations. 5. This study shows that learned behaviours may co-evolve as a consequence of antagonistic interactions, determining reciprocal cultural evolution or cultural co-evolution. As for (biological) co-evolution, the distribution of competing species influences whether a particular area becomes a syntopic environment in which convergence is occurring, or an allopatric environment lacking interactions and reciprocal change. Because of their plastic nature, cultural coadaptations may rapidly shift in response to fluctuating social selection, thus propelling dynamic interactions and fine adjustments to the local environment.
拮抗相互作用一直是物种共同进化研究的热门课题，因为竞争物种的共存通常会导致可量化的特征位移。竞争相互作用的一个常见结果是特征分歧，尽管在某些情况下，已经提出了相反的现象，即趋同进化，例如在维持相互排斥领地的物种的通讯行为中。
我在这里使用实验和观察证据来研究物种相互作用如何驱动异源信号趋同，并分析趋同如何以攻击行为的形式反馈到相互作用本身。我记录了两种非杂交云雀 Galerida cristata 和 G. theklae 的习得的领地信号，并使用异地种群作为同域的控制，以评估声学趋同。对社会条件进行了声学变化分析，以控制其他潜在的自然选择因素、栖息地和气候。
同域的 Galerida 叫声的种间趋同达到峰值。尽管叫声的声学结构受到气候和栖息地的影响，但即使在小的局部尺度上，它也与密度和与同域物种的接近程度的梯度相匹配。文化传播过程中，个体可以通过模仿邻居获得行为的组成部分，从而增强了叫声和当地社会环境之间的相关性。
两种物种都在争夺领地，但与异地同源叫声相比，趋同同源叫声的播放刺激引发了更强的攻击反应。
这项研究表明，习得的行为可能是由于拮抗相互作用而共同进化的，从而决定了互惠的文化进化或文化共同进化。与（生物）共同进化一样，竞争物种的分布影响特定区域是成为趋同发生的同域环境，还是缺乏相互作用和相互变化的异地环境。由于其可塑性，文化共同适应可能会迅速响应波动的社会选择而变化，从而推动动态相互作用和对当地环境的精细调整。
