Science. 1994 Mar 18;263(5153):1573-7. doi: 10.1126/science.263.5153.1573.
The serpent's forked tongue has intrigued humankind for millennia, but its function has remained obscure. Theory, anatomy, neural circuitry, function, and behavior now support a hypothesis of the forked tongue as a chemosensory edge detector used to follow pheromone trails of prey and conspecifics. The ability to sample simultaneously two points along a chemical gradient provides the basis for instantaneous assessment of trail location. Forked tongues have evolved at least twice, possibly four times, among squamate reptiles, and at higher taxonomic levels, forked tongues are always associated with a wide searching mode of foraging. The evolutionary success of advanced snakes might be due, in part, to perfection of this mechanism and its role in reproduction.
蛇类分叉的舌头千百年来一直令人类着迷，但它的功能却一直不为人知。现在，理论、解剖学、神经回路、功能和行为都支持这样一种假设，即分叉的舌头是一种用于追踪猎物和同类信息素踪迹的化学感觉边缘探测器。能够同时对化学梯度上的两个点进行采样，为即时评估轨迹位置提供了基础。在有鳞目爬行动物中，分叉的舌头至少进化了两次，也可能进化了四次，而在更高的分类学水平上，分叉的舌头总是与广泛的觅食搜索模式相关联。高级蛇类的进化成功可能部分归因于这种机制的完善及其在繁殖中的作用。
