A microbial game of thrones - from theory to application

细菌是微小的微生物，通常比人类头发的宽度还小一百倍，但它们加在一起仍然构成了地球上所有生物的很大一部分。它们也在很大程度上负责我们星球上化学元素的循环。它们是理解全球变暖后果的关键组成部分——全球变暖主要是由化石燃料燃烧引起的。在分子水平上，细菌比动物或植物表现出更多的生物多样性。在自然生态系统中，它们形成高度复杂和动态的群落。到目前为止，这些生物群落的生态环境与功能理论的发展背道而驰，功能理论可以用来理解自然界元素的循环，或者合理地设计细菌群落，让它们做一些有用的事情，比如生产可再生能源，以减缓全球变化。***两种相互竞争的生态学观点被称为“生态位”理论和“中性”理论。“生态位”观点认为，每一种细菌在自然界中都有其适当的位置，当环境有利于其特定特性时，它们将比竞争对手表现得更好。“中立”观点认为，许多不同的物种具有相似的特性，任何单一物种的生态成功都是由偶然过程决定的。然而，这两种观点都不能解释微生物群落仅由少数细菌主导的一般观察结果（与“生态位”理论一致），但却显示出这些赢家的明显随机更替（微生物权力的游戏，与“中性”理论一致）。***本研究采用了经济学的概念，探讨了“生态位”和“中性”的观点是否可以统一为一个总体的微生物生态学理论，以解释这些普遍的观察结果。我的中心前提是，在微生物生态学中，种群规模与生态适应度之间存在正相关关系，这是由短时间尺度的微观进化带来的。这个前提类似于财富和财富回报之间的正相关关系，经济学家用它来解释财富分配的高度不平等。***这项NSERC的发现研究旨在为这一新理论提供实验支持，并通过为可再生生物能源生产提供一个强大且具有成本效益的过程来应用它。该项目团队将在稳定条件下长期持续培养微生物群落，同时利用下一代DNA测序技术监测种群动态。总之，这些方法使我能够评估与新进化的生物多样性相关的潜在适应性益处。***如果成功，这项研究将对微生物生态学做出开创性的贡献，并有助于解决一个具有高度社会相关性的现实问题——一个经济上可行的可持续能源生产过程。

Bacteria are tiny microbes, typically a hundred times smaller than the width of a human hair, but together they still make up a large part of all living matter on Earth. They are also largely responsible for the cycling of the chemical elements on our planet. They are a key component in understanding the consequences of global warming - brought about mainly by fossil fuel burning.***At the molecular level, bacteria display much more biodiversity than animals or plants. In natural ecosystems they form highly complex and dynamic communities. The ecology of these communities has so far defied the development of functional theory that can be used to understand the cycling of the elements in nature, or to rationally design bacterial communities to do useful things like production of renewable energy to mitigate global change.***Two competing ecological perspectives are known as "niche" and "neutral" theory. The "niche" perspective holds that each bacterium has its proper place in nature and will outperform its competitors when the environment favours its specific properties. The "neutral" perspective holds that many different species have similar properties and the ecological success of any single species is determined by chance processes. However, neither perspective can explain general observations that microbial communities are dominated by only a handful of bacteria (consistent with "niche" theory) yet show apparently random turnover of these winners (the microbial game of thrones, consistent with "neutral" theory).***Adopting concepts from the economical sciences, the proposed research investigates whether the "niche" and "neutral" perspectives can be unified into an overarching theory for microbial ecology that can explain those general observations. My central premise is that in microbial ecology there exists a positive relationship between population size and ecological fitness, brought about by micro-evolution on short timescales. This premise is analogous to the positive relationship between wealth and returns on wealth, that economists use to explain the very high inequality in wealth distributions.***This NSERC discovery research aims to generate experimental support for this new theory - and to apply it, by contributing to a robust and cost-effective process for renewable bio-energy production. The program's team will perform long-term continuous cultivation of microbial communities under stable conditions, while monitoring population dynamics with next generation DNA sequencing technology. Together, these approaches enable me to assess potential fitness benefits associated with newly evolved biodiversity.***If successful, the research will make a groundbreaking contribution to microbial ecology and contribute to a real-world problem of high societal relevance - an economically feasible process for sustainable energy production.