Coevolution of cooperative lifestyles and reduced cancer prevalence in mammals

Why cancer is so prevalent among mammals, despite the fact that some species evolved resistance mechanisms, remains an open question. We hypothesized that cancer prevalence and mortality risk might have been fine-tuned by evolution. Using public databases, we show that species with cooperative habits have lower cancer prevalence and mortality risk. By developing a mathematical model, we provide a mechanistic explanation: an oncogenic variant that elicits higher cancer mortality in older and less reproductive individuals is detrimental to cooperative mammalian societies but can lead to a counterintuitive overcompensation in population size and fitness within competitive contexts. The phenomenon of a population increasing in response to a decrease in its per capita survival rate is called the hydra effect, a process never explored in the field of cancer before. Therefore, cancer can be considered as a selected mechanism of biological obsolescence in competitive species.
, See the following DOI: 10.1126/sciadv.adw0685 (available on November 12, 2025)
CMR, neoplasia and malignancy prevalence in mammalian species
First dataset: Cancer Mortality Risk (CMR) was calculated for each species as the proportion of cancer-related deaths out of the total number of records, based on post-mortem pathological records (n=11,840). This information was sourced from Species360 and The Zoological Information Management System (ZIMS). The dataset initially included 191 species, but D. byrnei was removed due to its extremely high CMR, which was considered an outlier. This CMR data was gathered from mammals in zoos worldwide, providing high-resolution cause-of-death data. CMR was estimated from neoplastic samples that substantially contributed to the animal death, as confirmed by necropsies. The CMR estimated for each and every species included in this dataset is based on more than 20 necropsies per species (mean = 62).
Second dataset: Prevalence of neoplasia was estimated as ..., # Data from: Coevolution of cooperative lifestyles and reduced cancer prevalence in mammals

Dataset DOI: [10.5061/dryad.xgxd254vh](https://doi.org/10.5061/dryad.xgxd254vh)

## Description of the data and file structure

Dataset1.csv

Cancer mortality risk (CMR) was calculated for each species as the proportion of cancer-related deaths among the total number of records, based on post-mortem pathological records (n = 11,840, Vincze et al., 2022). This information was sourced from Species360 and The Zoological Information Management System. The dataset initially included 191 species, but Dasyuroides byrnei was removed because of its extremely high CMR, which was considered an outlier. This CMR data were gathered from mammals in zoos worldwide, providing high-resolution cause-of-death data. CMR was estimated from neoplastic samples that substantially contributed to the animal death, as confirmed by necropsies. The CMR estimated for every species included in this dataset is based on more th...,

尽管部分哺乳动物类群演化出抗癌抗性机制，但癌症在哺乳动物中仍普遍高发，这一问题至今仍是尚未解决的科学议题。我们提出假说：癌症患病率与死亡风险或许是演化过程中精细调控的结果。借助公共数据库，我们发现具有协作习性的物种，其癌症患病率与癌症相关死亡风险均更低。通过构建数学模型，我们从机制层面给出了解释：一类致癌变异会在年老且繁殖能力下降的个体中引发更高的癌症死亡率，这对协作型哺乳动物社会而言是不利的；但在竞争环境下，该变异却会带来反直觉的种群规模与适合度过度补偿效应。种群因个体存活率下降而出现规模增长的现象被称为水螅效应（hydra effect），这一过程此前从未在癌症研究领域被探讨过。因此，我们可以将癌症视为竞争型物种中生物衰老的一种选择机制。

详见以下DOI：10.1126/sciadv.adw0685（发布于2025年11月12日）
哺乳动物癌症死亡率风险（Cancer Mortality Risk, CMR）、肿瘤形成与恶性肿瘤患病率数据集
第一个数据集：基于尸检病理记录（样本量n=11840），我们将每个物种的癌症死亡率风险（CMR）计算为癌症相关死亡数占总记录数的比例。该数据来源于Species360与动物信息管理系统（Zoological Information Management System, ZIMS）。初始数据集共包含191个物种，但由于D. byrnei的CMR值极高，被判定为异常值后已被移除。本数据集的CMR数据采集自全球动物园中的哺乳动物，提供了高分辨率的死因数据。CMR的估算基于经尸检确认的、显著导致动物死亡的肿瘤样本。本数据集纳入的每个物种的CMR估算值，均基于该物种至少20次尸检结果（平均为62次）。

第二个数据集：肿瘤形成患病率估算为……，数据来源：《协作生活方式与哺乳动物癌症患病率的协同演化》
数据集DOI：[10.5061/dryad.xgxd254vh](https://doi.org/10.5061/dryad.xgxd254vh)

## 数据与文件结构说明
Dataset1.csv
癌症死亡率风险（CMR）的计算方式为：以尸检病理记录（样本量n=11840，Vincze等，2022）为基础，将癌症相关死亡数占总记录数的比例作为各物种的CMR值。该信息来源于Species360与动物信息管理系统。初始数据集共包含191个物种，但由于Dasyuroides byrnei的CMR值极高，被判定为异常值后已被移除。本数据集的CMR数据采集自全球动物园中的哺乳动物，提供了高分辨率的死因数据。CMR的估算基于经尸检确认的、显著导致动物死亡的肿瘤样本。本数据集纳入的每个物种的CMR估算值，均基于该物种至少20次尸检结果……