European Centre for Environment and Human Health, University of Exeter Medical School, Environment and Sustainability Institute, Treliever Road, Penryn Campus, Penryn, TR10 9FE, United Kingdom.
Environment and Sustainability Institute, University of Exeter, Treliever Road, Penryn Campus, Penryn, TR10 9FE, United Kingdom.
FEMS Microbiol Ecol. 2023 Nov 13;99(12). doi: 10.1093/femsec/fiad154.
Prokaryote diversity makes up most of the tree of life and is crucial to the functioning of the biosphere and human health. However, the patterns and mechanisms of prokaryote diversification have received relatively little attention compared to animals and plants. Adaptive radiation, the rapid diversification of an ancestor species into multiple ecologically divergent species, is a fundamental process by which macrobiological diversity is generated. Here, we discuss whether ecological opportunity could lead to similar bursts of diversification in bacteria. We explore how adaptive radiations in prokaryotes can be kickstarted by horizontally acquired key innovations allowing lineages to invade new niche space that subsequently is partitioned among diversifying specialist descendants. We discuss how novel adaptive zones are colonized and exploited after the evolution of a key innovation and whether certain types of are more prone to adaptive radiation. Radiation into niche specialists does not necessarily lead to speciation in bacteria when barriers to recombination are absent. We propose that in this scenario, niche-specific genes could accumulate within a single lineage, leading to the evolution of an open pangenome.
原核生物多样性构成了生命之树的大部分，对生物圈的功能和人类健康至关重要。然而，与动物和植物相比，原核生物多样化的模式和机制相对较少受到关注。适应辐射是一种基本过程，通过这种过程，宏观生物多样性得以产生，即一个祖先物种快速多样化成为多个生态上不同的物种。在这里，我们讨论生态机会是否会导致细菌发生类似的多样化爆发。我们探讨了水平获得的关键创新如何使谱系能够入侵新的生态位空间，随后这些生态位空间在多样化的专业后裔中进行划分，从而引发原核生物的适应辐射。我们讨论了在关键创新进化后，新的适应区是如何被殖民和利用的，以及某些类型的创新是否更容易发生适应辐射。当不存在重组障碍时，细菌中的辐射到生态位专化种不一定会导致物种形成。我们提出，在这种情况下，特定于生态位的基因可能在单个谱系内积累，导致开放泛基因组的进化。
