CoMPLEX, University College London, Gower Street, London W1E 6BT, UK
Philos Trans R Soc Lond B Biol Sci. 2018 Apr 5;373(1743). doi: 10.1098/rstb.2017.0063.
The effect of environmental change on the rate of innovation and level of cultural complexity in a population is a theoretically understudied piece of an important puzzle at the heart of cultural evolution. Many mathematical models of cultural complexity have focused on the role of demographic factors such as population size or density. However, statistical studies often point to environmental variability as an important factor determining complexity in many cases. The aim of this study is to explore the interaction between environmental fluctuations and the rate of cultural innovation within a population and to examine the relationship between rates of innovation and the probability of maintaining a complex cultural repertoire in a changing environment. Two models are presented that draw on previous models used to examine rates of genetic mutation. The models show that, as in a genetic system, the stable rate of cultural innovation in a population decreases with environmental stability and increases in unstable environments. This effect is similar but quantitatively different for different modes of cultural transmission (success bias, conformity bias and random oblique learning). The model shows that innovation can increase diversity but that this relationship depends critically on learning mode and learning parameters.This article is part of the theme issue 'Bridging cultural gaps: interdisciplinary studies in human cultural evolution'.
环境变化对群体创新速度和文化复杂性水平的影响是文化进化核心重要谜题中一个理论上研究不足的部分。许多文化复杂性的数学模型都集中在人口统计学因素（如人口规模或密度）的作用上。然而，统计研究经常指出，在许多情况下，环境可变性是决定复杂性的一个重要因素。本研究旨在探讨环境波动与群体内部文化创新速度之间的相互作用，并研究创新速度与在不断变化的环境中维持复杂文化库的概率之间的关系。提出了两个模型，它们借鉴了以前用于检查遗传突变率的模型。这些模型表明，与遗传系统一样，种群中稳定的文化创新率随环境稳定性的降低而降低，在不稳定的环境中增加。对于不同的文化传播模式（成功偏差、从众偏差和随机倾斜学习），这种影响相似但在数量上有所不同。该模型表明，创新可以增加多样性，但这种关系取决于学习模式和学习参数。本文是主题为“弥合文化差距：人类文化进化的跨学科研究”的一部分。
