The ecology and evolution of sibling cannibalism in the wild

同类相食是一种几乎所有分类类群都表现出的行为，它可以分为几个亚型。食用自己的兄弟姐妹，兄弟姐妹食人，提出了一个有趣的案例，因为它需要吃一个与自己共享大约50%基因组成的亲戚的有点违反直觉的行为。理解在物种/个体中表达的同胞相残程度的进化和生态原因是一个多方面的任务。同类相食的倾向受到几个生态因素的影响（例如，营养益处和疾病成本），具有相反的效果。此外，同类相食的倾向可能会受到与食用亲属相关的进化适应性成本的影响。一窝同类相食的水平也可能受到母亲的影响，因为窝内同类相食可以减少或增加母亲的进化适应性，这取决于生态环境。因此，兄弟姐妹之间的同类相食可能成为兄弟姐妹之间和母子之间冲突的根源。作为一个复杂而迷人的研究领域，研究同类相食可能有助于进一步发展进化理论的知识，如汉密尔顿规则，并有利于经济研究（例如，在农业）和保护（在入侵物种的研究）的重要性。 迄今为止，同胞相残的研究受到其研究物种的物种多样性低，缺乏实地调查的经验数据。创建一个具有更大物种多样性的研究框架可能有助于构建一个更普遍的知识基础，在生态和进化框架中，驱动食人的流行。拥有这样一个基地可以使未来关于食人的研究更有效地取得进展，更容易做出预测。由于同类相食行为在实验室和更自然的环境中可能会有不同的表现，因此必须增加在实地对同类相食所做的工作量，以了解实验室研究如何解释野生种群的行为。 该项目旨在进一步了解昆虫同胞相残的进化和生态驱动因素，特别是在Lygaeidae（一组真正的昆虫，已经进行了小同胞相残研究）和瓢虫科（瓢虫，一组包含可能因相残而成为更有效入侵者的物种）中，使用实验室和实地研究相结合的方法。实验室工作最初将集中在测试的想法兄弟姐妹和母子冲突的同类相食，研究的影响包容性健身成本的同类相食在Lygaeids（并在这样做开发的方法来研究同类相食在以前研究不足的组）和母亲的参与影响育雏同类相食水平在Lygaeids和Coccinellids。测试母亲参与的工作也可以扩展到考虑同类相食和其他相关特征的遗传性，这是一个以前从进化角度很少关注的主题。实地考察将包括考虑周围的食物丰富的食同类水平在Lygaeids和瓢虫科的影响，并使用分子遗传技术的昆虫集群的相关性结构的推导。

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.