Hochberg Michael E, Noble Robert J
Intstitut des Sciences de l'Evolution de Montpellier, Université de Montpellier, Place E. Bataillon, CC065, 34095, Montpellier Cedex 5, France.
Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM, 87501, USA.
Ecol Lett. 2017 Feb;20(2):117-134. doi: 10.1111/ele.12726. Epub 2017 Jan 16.
Evolutionary theory explains why metazoan species are largely protected against the negative fitness effects of cancers. Nevertheless, cancer is often observed at high incidence across a range of species. Although there are many challenges to quantifying cancer epidemiology and assessing its causes, we claim that most modern-day cancer in animals - and humans in particular - are due to environments deviating from central tendencies of distributions that have prevailed during cancer resistance evolution. Such novel environmental conditions may be natural and/or of anthropogenic origin, and may interface with cancer risk in numerous ways, broadly classifiable as those: increasing organism body size and/or life span, disrupting processes within the organism, and affecting germline. We argue that anthropogenic influences, in particular, explain much of the present-day cancer risk across life, including in humans. Based on a literature survey of animal species and a parameterised mathematical model for humans, we suggest that combined risks of all cancers in a population beyond c. 5% can be explained to some extent by the influence of novel environments. Our framework provides a basis for understanding how natural environmental variation and human activity impact cancer risk, with potential implications for species ecology.
进化理论解释了为什么后生动物物种在很大程度上受到保护，免受癌症对适应性的负面影响。然而，在一系列物种中经常观察到癌症的高发病率。尽管在量化癌症流行病学和评估其病因方面存在许多挑战，但我们认为，动物尤其是人类中大多数现代癌症是由于环境偏离了在癌症抗性进化过程中普遍存在的分布中心趋势。这种新的环境条件可能是自然的和/或人为的，并且可能以多种方式与癌症风险相互作用，大致可分为以下几种：增加生物体的体型和/或寿命、扰乱生物体内的过程以及影响种系。我们认为，特别是人为影响解释了当今整个生命过程中的大部分癌症风险，包括人类的癌症风险。基于对动物物种的文献调查和针对人类的参数化数学模型，我们表明，人群中所有癌症的综合风险超过约5%，在一定程度上可以通过新环境的影响来解释。我们的框架为理解自然环境变化和人类活动如何影响癌症风险提供了基础，对物种生态学具有潜在意义。
