Host-parasite coevolution in complex communities

宿主如何进化以科普传染病的威胁？引起传染病的寄生虫如何进化以克服宿主的防御？这些是推动我的研究的关键问题，我的研究旨在了解宿主和寄生虫之间持续的进化之战。研究宿主和寄生虫如何“共同进化”，不仅对控制传染病有重要意义，而且对回答自然界的基本问题也有重要意义，所有生物体都会遭受寄生虫引起的传染病，其中许多会对宿主健康造成严重影响，甚至致命。因此，宿主已经进化出各种应对寄生虫的方法，从复杂而昂贵的免疫系统识别和消除微观病原体，到清除外部寄生虫的梳理行为。同样地，寄生虫也进化出迷人的方式来避免或克服宿主的防御（例如通过分泌抑制免疫反应的蛋白质），甚至操纵宿主行为以最大限度地传播。寄生虫和寄生虫存在于不同的多物种群落中，这有可能通过增加对资源的竞争或改变与国防和反防御特征例如，捕食可能会通过减少宿主的可用性（资源竞争）来增加对寄生虫的压力，并且如果疾病变得罕见（权衡），则可能会阻止代价高昂的抗性机制的进化。然而，我们目前对宿主-寄生虫共同进化如何受到更广泛的生态群落（例如其他宿主和寄生虫，捕食者，猎物等）的影响知之甚少。本研究计划的目的是了解更广泛的生态群落中的物种对宿主和寄生虫进化的影响。为了实现这一目标，我将使用数学模型和计算机模拟来揭示影响宿主和寄生虫在其他物种存在下共同进化的潜在过程和机制。我也将与生态学家合作来测试新的理论，并使用实验观察来反馈和进一步发展理论。我将首先通过分析不同的相互作用网络来研究生态群落的结构如何影响共同进化动力学。然后，我将利用我所获得的关于更广泛的生态社区的影响的知识来研究多种宿主和寄生虫特征的共同进化。这将使我能够回答一些问题，比如：感染多个宿主的寄生虫是否更有可能致命？宿主什么时候应该优先考虑适应性防御而不是先天防御？最后，我将与实验学家合作，通过细菌和病毒的共同进化来测试和改进这一理论。我的研究将为基本生物现象提供关键见解，例如生物多样性是如何产生和维持的，以及寄生虫在宿主交配行为进化中所扮演的角色。虽然我的工作是理论性的，但它对公共卫生有重要意义。例如，病毒可用于治疗抗生素耐药性感染（噬菌体疗法），但了解其他微生物物种的存在如何影响细菌进化以最大限度地提高治疗效果至关重要。这对工业和保护也有影响，特别是在预测人类干预或环境变化如何影响自然生态系统或受管理种群的稳定性方面。

How do hosts evolve to cope with the threat of infectious diseases? How do parasites that cause infectious diseases evolve to overcome host defences? These are the key questions that drive my research, which seeks to understand the continual evolutionary battle between hosts and parasites. Studying how host and parasites "co-evolve" not only has important implications for controlling infectious diseases, but also for answering fundamental questions about the natural world.All living organisms suffer from infectious diseases caused by parasites, many of which have a serious impact on host health and can be fatal. As such, hosts have evolved a variety of ways of coping with parasitism, from complex and expensive immune systems that recognise and eliminate microscopic pathogens, to grooming behaviour that removes external parasites. Likewise, parasites have evolved fascinating ways of avoiding or overcoming host defences (e.g. by secreting proteins that suppress immune responses), and even manipulating host behaviour to maximise transmission.Hosts and parasites exist in diverse multi-species communities, which have the potential to impact their evolution through increased competition for resources or changes in cost-benefit trade-offs associated with investing in defence and counter-defence traits. For example, predation may increase pressure on parasites by reducing host availability (resource competition) and may prevent a costly resistance mechanism from evolving if disease becomes rare (trade-offs). However, we currently know very little about how host-parasite coevolution is affected by the wider ecological community (e.g. other hosts and parasites, predators, prey, etc).The aim of this research programme is to understand the impact of species in the wider ecological community on the evolution of hosts and parasites. To achieve this, I will use mathematical models and computer simulations to reveal the underlying processes and mechanisms that affect how hosts and parasites co-evolve in the presence of other species. I will also collaborate with empiricists to test the new theory and use experimental observations to feed back and further develop the theory.I will first investigate how the structure of the ecological community affects co-evolutionary dynamics by analysing different networks of interactions. I will then use the knowledge that I have gained about the impact of the wider ecological community to examine the co-evolution of multiple host and parasite traits. This will allow me to answer questions such as: are parasites that infect multiple hosts more likely to be deadly? And when should hosts prioritise adaptive defences over innate defences? Finally, I will work with experimentalists to test and improve the theory by coevolving bacteria and viruses.My research will provide key insights into fundamental biological phenomena, such as how biodiversity is generated and maintained and the role that parasites play in the evolution of host mating behaviour. Although my work is theoretical, it has important implications for public health. For example, viruses can be used to treat antibiotic resistant infections (phage therapy), but it is crucial to understand how the presence of other microbial species affects bacterial evolution to maximise treatment efficacy. There are consequences for industry and conservation, as well, especially for predicting how human interventions or environmental changes affect the stability of natural ecosystems or managed populations.