Declining mortality seems a natural explanation for the demographic transition. However, many economists have discarded improved infant survival as a causal trigger. Moreover, certain currents in Neo-Malthusian economics point to potentially beneficial side-effects of population shocks. Based on historical demography and evolutionary science, I challenge these views. The argument is that uncontrollable (“extrinsic”) mortality creates selective advantages for families with many “cheap” offspring, whereas stable environments favor child “quality”. Combining “life-history-theory” and a unified growth model, I demonstrate that declining mortality and medical progress facilitate the transition towards growth-promoting “low-fertility-high-quality” phenotypes. As it will turn out, this framework produces qualitatively and quantitatively closer predictions of the historical fertility decline than standard models of the Barro–Becker type. Moreover, evolutionary mechanisms provide a parsimonious explanation for diverse demographic transition patterns. Thus, evolved adaptations add a new and culture-free mechanism to older theories. Moreover, regarding sustainable growth, they suggest that natural selection eventually offsets the benefits from population shocks claimed by Malthusian theories.

死亡率下降似乎是人口转变的自然解释。然而，许多经济学家已经将婴儿存活率的提高视为因果触发因素。此外，新马尔萨斯经济学中的某些潮流指出了人口冲击的潜在有益副作用。基于历史人口学和进化科学，我挑战这些观点。论点是，无法控制的（“外在”）死亡率为拥有许多“廉价”后代的家庭创造了选择性优势，而稳定的环境有利于孩子的“质量”。结合“生活-历史-理论”和统一的增长模型，我证明了死亡率的下降和医学进步促进了向促进生长的“低生育率-高质量”表型的转变。事实证明，与 Barro-Becker 类型的标准模型相比，该框架在定性和定量上对历史生育率下降的预测更接近。此外，进化机制为不同的人口转变模式提供了简洁的解释。因此，进化的适应为旧理论增加了一种新的和无文化的机制。此外，关于可持续增长，他们认为自然选择最终会抵消马尔萨斯理论声称的人口冲击带来的好处。