Jia Tony Z, Caudan Melina, Mamajanov Irena
Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
Blue Marble Space Institute of Science, 1001 4th Ave., Suite 3201, Seattle, WA 98154, USA.
Life (Basel). 2021 Feb 17;11(2):154. doi: 10.3390/life11020154.
Speciation, an evolutionary process by which new species form, is ultimately responsible for the incredible biodiversity that we observe on Earth every day. Such biodiversity is one of the critical features which contributes to the survivability of biospheres and modern life. While speciation and biodiversity have been amply studied in organismic evolution and modern life, it has not yet been applied to a great extent to understanding the evolutionary dynamics of primitive life. In particular, one unanswered question is at what point in the history of life did speciation as a phenomenon emerge in the first place. Here, we discuss the mechanisms by which speciation could have occurred before the origins of life in the context of chemical evolution. Specifically, we discuss that primitive compartments formed before the emergence of the last universal common ancestor (LUCA) could have provided a mechanism by which primitive chemical systems underwent speciation. In particular, we introduce a variety of primitive compartment structures, and associated functions, that may have plausibly been present on early Earth, followed by examples of both discriminate and indiscriminate speciation affected by primitive modes of compartmentalization. Finally, we discuss modern technologies, in particular, droplet microfluidics, that can be applied to studying speciation phenomena in the laboratory over short timescales. We hope that this discussion highlights the current areas of need in further studies on primitive speciation phenomena while simultaneously proposing directions as important areas of study to the origins of life.
物种形成是一个新物种形成的进化过程，它最终造就了我们每天在地球上所观察到的令人惊叹的生物多样性。这种生物多样性是有助于生物圈和现代生命生存能力的关键特征之一。虽然物种形成和生物多样性在有机进化和现代生命中已得到充分研究，但在很大程度上尚未应用于理解原始生命的进化动态。特别是，一个尚未得到解答的问题是，在生命历史的哪个阶段物种形成现象首先出现。在这里，我们讨论在化学进化背景下生命起源之前物种形成可能发生的机制。具体而言，我们讨论在最后一个共同祖先（LUCA）出现之前形成的原始区室可能为原始化学系统经历物种形成提供了一种机制。特别是，我们介绍了各种可能在早期地球上存在的原始区室结构及其相关功能，接着列举了受原始区室化模式影响的区分性和非区分性物种形成的例子。最后，我们讨论了现代技术，特别是微滴微流控技术，它可应用于在实验室短时间尺度上研究物种形成现象。我们希望这次讨论突出了当前在原始物种形成现象进一步研究中需要关注的领域，同时为生命起源的重要研究方向提出建议。
