The ecology and evolution of sibling cannibalism in the wild

食人是几乎所有分类类群都表现出的一种行为，它可以分为几个亚型。吃自己的兄弟姐妹，即兄弟姐妹食人，是一个有趣的案例，因为它涉及到吃一个与自己有大约50%基因组成的亲戚的行为，这多少有点违反直觉。理解一个物种/个体表现出的同胞相残程度的进化和生态学原因是一项多方面的任务。吃人的倾向受到几个生态因素的影响(如营养效益和疾病成本)，但影响是相反的。此外，食人倾向可能会受到与消耗亲属相关的进化健康成本的影响。幼崽中的食人水平也可能受到母亲的影响，因为根据生态环境的不同，幼崽中的食人行为可以降低或增加母亲的进化适合度。因此，兄弟姐妹相食可能是兄弟姐妹和母子冲突的一个来源。除了是一个复杂而迷人的研究领域，研究食人现象可能有助于进一步发展关于汉密尔顿法则等进化理论的知识，并有助于具有经济(例如，农业)和保护(在入侵物种研究)重要性的研究。到目前为止，对兄弟姐妹食人的研究受到其研究物种的物种多样性低以及缺乏基于实地考察的经验数据的限制。创建一个具有更大物种多样性的研究框架，可能有助于建立一个更具普遍性的知识库，在生态和进化框架中，是什么推动了食人现象的流行。拥有这样的基地可以使未来对食人族的研究更有效地进行，更容易做出预测。由于食人行为在实验室和更自然的环境中可能表现出不同的表现，因此必须增加在野外对吃人行为所做的工作，以了解实验室研究如何能够很好地解释野生种群的行为。该项目旨在通过实验室和现场研究相结合的方式，进一步了解昆虫中兄弟姐妹相食的进化和生态驱动因素，特别是在Lygaeidae(一组真正的虫子，几乎没有对它们进行同胞相食研究)和瓢虫科(瓢虫，一组包含可能由于吃人而更有效的入侵者的物种)。实验室工作最初将集中在测试兄弟姐妹和母子冲突对吃人的影响，研究利盖德人吃人的包容性适应成本的影响(并在这样做的过程中开发方法来研究以前未被研究的群体中的人吃人)，以及母亲参与影响利盖德人和瓢虫的幼虫吃人的水平。测试母亲参与的工作也可以扩展到考虑吃人和其他相关特征的遗传性，这是一个以前从进化论的角度很少引起注意的问题。实地考察工作将包括考虑周围食物丰度对狼蛛科和瓢虫科同类水平的影响，以及利用分子遗传技术推断昆虫群落的亲缘结构。

Cannibalism is a behaviour displayed by nearly all taxonomic groups and it can be divided into several subtypes. The consumption of one's own siblings, sibling cannibalism, presents an interesting case as it entails the somewhat counterintuitive act of eating a relative with whom one shares approximately 50% of its genetic makeup. Understanding the evolutionary and ecological reasons for the degree of sibling cannibalism expressed in a species/individual is a multi-faceted task. Propensity for cannibalism is influenced by several ecological factors (e.g., nutritional benefits and diseases costs) with opposing effects. Additionally, cannibalism propensity can be influenced by the evolutionary fitness costs associated with consuming a relative. Cannibalism levels within a brood may also be influenced by mothers, as within-brood cannibalism can either decrease or increase a mother's evolutionary fitness, depending on the ecological context. Sibling cannibalism can therefore be a source of sibling-sibling and mother-offspring conflict. As well as being a complex and fascinating area of research, studying cannibalism may facilitate further development of knowledge on evolutionary theories such as Hamilton's rule, and can benefit research with economic (e.g., in agriculture) and conservational (in the study of invasive species) importance. To date, research on sibling cannibalism is constrained by the low species diversity of its study species and by its lack of fieldwork-based empirical data. Creating a research framework with greater species diversity may facilitate the construction of a more generalisable knowledge base on what, in an ecological and evolutionary framework, drives cannibalism's prevalence. Possession of such a base could allow future research on cannibalism to progress more effectively, with a greater ease of making predictions. As cannibalistic behaviours may be expressed differently in lab vs. more natural settings it is imperative to increase the amount of work which has been done on cannibalism in the field to see how well laboratory studies can explain the behaviour of wild populations. This project aims to further understand the evolutionary and ecological drivers of sibling cannibalism in insects, specifically in the Lygaeidae (a group of true bugs for whom little sibling cannibalism research has been done) and the Coccinellidae (Ladybirds, a group containing species who may be more efficient invaders due to cannibalism), using a combination of lab and field-based study. Lab work will initially focus on testing ideas of sibling-sibling and mother-offspring conflict over cannibalism, studying the implications of inclusive fitness costs of cannibalism in Lygaeids (and in doing so developing methods to study cannibalism in a previously understudied group) and the involvement of mothers in influencing brood cannibalism levels in both Lygaeids and Coccinellids. The work testing the mother's involvement can also be expanded to consider the heritability of cannibalism and other correlated traits, a subject which has previously garnered little attention from an evolutionary perspective. Fieldwork will include considerations of the influence of surrounding food abundance on cannibalism levels in both Lygaeids and the Coccinellidae, and deduction of the relatedness structure of insect clusters using molecular genetic techniques.