The Flask model: emergence of nutrient‐recycling microbial ecosystems and their disruption by environment‐altering ‘rebel’ organisms
The Flask model: emergence of nutrient‐recycling microbial ecosystems and their disruption by environment‐altering ‘rebel’ organisms
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Flask 模型：营养循环微生物生态系统的出现及其被改变环境的“反叛”生物体破坏
DOI：
10.1111/j.0030-1299.2007.15721.x
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发表时间：
2007
期刊：
影响因子：
3.4
通讯作者：
T. Lenton
中科院分区：
文献类型：
--
作者：
Hywel T. P. Williams;T. Lenton
在这里，我们介绍了一种新的生命-环境相互作用模型，该模型模拟了液体“烧瓶”中不断变化的微生物群落，并输入了规定的营养物质。烧瓶中接种了一群“微生物”，这些微生物的基因位点会发生突变，这些基因位点决定了它们的营养吸收模式、释放模式及其对其他环境变量的影响和反应。与现有的生命-环境相互作用模型（尤其是 Daisyworld）相比，对个体生物体的益处与它们的“全局”（系统级）影响是脱钩的。该模型的一个强大特性是生态系统的出现，这些生态系统倾向于养分被有效利用和差异化回收的状态，同时总人口也随之增加。生物体改变环境是其生长的免费“副产品”，而它们的生长受到不利环境影响的限制。这引入了环境反馈，这可能会破坏模型生态系统，尽管理论上生物体可以适应的条件没有限制。 “反叛”生物体可能会通过利用未充分利用的资源而快速生长，但这样做会使环境远离大多数社区所适应的状态。结果可能是人口崩溃和回收损失，随后恢复，或者在极端情况下，系统完全灭绝。这些“烧瓶”生态系统的大量运行表明，对生长的更严格的环境限制使系统更容易受到内部产生的生态系统灭绝的影响。
Here we introduce a new model of life-environment interaction, which simulates an evolving microbial community in a 'Flask' of liquid with prescribed inputs of nutrients. The flask is seeded with a clonal population of 'microbes' that are subject to mutation on genetic loci that determine their nutrient uptake patterns, release patterns, and their effects on, and response to, other environmental variables. In contrast to existing models of life-environment interaction, notably Daisyworld, what benefits the individual organisms is decoupled from their 'global' (system-level) effects. A robust property of the model is the emergence of ecosystems that tend toward a state where nutrients are efficiently utilised and differentially recycled, with a correlated increase in total population. Organisms alter the environment as a free 'by-product' of their growth, and their growth is constrained by adverse environmental effects. This introduces environmental feedback, which can disrupt the model ecosystems, even though there are no constraints on the conditions to which the organisms can theoretically adapt. 'Rebel' organisms can appear that grow rapidly by exploiting an under-utilised resource, but in doing so shift the environment away from the state to which the majority of the community are adapted. The result can be a population crash with loss of recycling, followed by later recovery, or in extreme cases, a total extinction of the system. Numerous runs of these 'flask' ecosystems show that tighter environmental constraints on growth make the system more vulnerable to internally generated ecosystem extinction.
DOI：
10.1073/pnas.96.18.10242
发表时间：
1999-08-31
影响因子：
11.1
作者：
Laland, KN;Odling-Smee, FJ;Feldman, MW
通讯作者：
Feldman, MW