The study of evolution and development together, ‘evo-devo’, is essential to understand sensitive periods. The combination of phylogenetic history, life history, the biophysics of developing physical substrates, as well as cognitive and neural mechanisms, can distinguish their accidental from essential features. Two examples of research programs concerning sensitive periods, the calibration of eye growth by visual experience versus parameter-setting in early speech and language development are contrasted. The satisfactory resolution produced by the multi-level analysis of eye calibration compared to the enduring controversies generated by the exclusive focus on behavioral and cognitive mechanisms in speech and language research are striking. Evo-devo can also reframe classic subjects. ‘Object recognition’, often assumed to be vision’s central function, in phylogenetic perspective emerges as a specialized human adaptation with an unusual sensitive period. Theory-building must go hand in hand with rich description of the sequences of physical states in full evolutionary context to explain any cognitive capacity constructed by the interaction of organism and environment.

一起研究进化与发展，“进化”，对于理解敏感时期至关重要。系统发育史，生活史，发展中的物理底物的生物物理学以及认知和神经机制的结合，可以将其偶然性与基本特征区分开。对比了两个有关敏感时期的研究程序示例，即通过视觉体验对眼睛生长进行校准与早期语音和语言发展中的参数设置进行对比。与语音和语言研究中仅关注行为和认知机制而引起的持久争议相比，通过眼部校准的多层次分析产生的令人满意的分辨率令人震惊。Evo-devo还可以重新构造经典主题。“物体识别”，通常被认为是视觉的中心功能，在系统发生学中，它是一种特殊的人类适应过程，具有异常的敏感期。理论构建必须与在完整的进化背景下对物理状态序列的丰富描述齐头并进，以解释由有机体与环境的相互作用所构建的任何认知能力。