Data from: Infection of the fittest: devil facial tumour disease has greatest effect on individuals with highest reproductive output

Emerging infectious diseases rarely affect all members of a population
equally and determining how individuals’ susceptibility to infection is
related to other components of their fitness is critical to understanding
disease impacts at a population level and for predicting evolutionary
trajectories. We introduce a novel state-space model framework to
investigate survival and fecundity of Tasmanian devils (Sarcophilus
harrisii) affected by a transmissible cancer, devil facial tumour disease.
We show that those devils that become host to tumours have otherwise
greater fitness, with higher survival and fecundity rates prior to
disease-induced death than non-host individuals that do not become
infected, although high tumour loads lead to high mortality. Our finding
that individuals with the greatest reproductive value are those most
affected by the cancer demonstrates the need to quantify both survival and
fecundity in context of disease progression for understanding the impact
of disease on wildlife populations.

新发传染病极少会对种群内所有个体造成均等影响。明确个体的感染易感性与其适合度（fitness）的其他组成维度之间的关联，对于解析疾病在种群层面的影响、预测疾病演化轨迹均至关重要。本研究提出一种全新的状态空间模型（state-space model）框架，用于探究受可传播性癌症——袋獾面部肿瘤病（devil facial tumour disease）——侵染的袋獾（Sarcophilus harrisii）的存活能力与繁殖力。研究结果表明，成为肿瘤宿主的袋獾在其他生命特征维度上具备更高的适合度：在因疾病致死前，其存活率与繁殖力均高于未受感染的非宿主个体，尽管高肿瘤负荷会引发较高的死亡率。本研究发现，拥有最高繁殖价值的个体恰恰是受该癌症影响最严重的群体，这一结论表明，若要解析疾病对野生种群的影响，必须结合疾病进展过程量化个体的存活与繁殖能力。