Symbiogenesis: Beyond the endosymbiosis theory?

JOURNAL OF THEORETICAL BIOLOGY

卷:434

Article

Aanen, Duur K.¹  Eggleton, Paul² 

[1] Wageningen Univ, Lab Genet, Dept Plant Sci, NL-6708 PB Wageningen, Netherlands

[2] Nat Hist Museum, Life Sci Dept, London SW7 5BD, England

关键词: Cockroaches;    Endosymbiosis theory;    Eusociality;    Flagellates;    Gut symbionts;    Insects;    Termites;   

DOI  :  10.1016/j.jtbi.2017.08.001

来源: Elsevier

【 摘 要 】

Symbiogenesis, literally 'becoming by living together', refers to the crucial role of symbiosis in major evolutionary innovations. The term usually is reserved for the major transition to eukaryotes and to photosynthesising eukaryotic algae and plants by endosymbiosis. However, in some eukaryote lineages endosymbionts have been lost secondarily, showing that symbiosis can trigger a major evolutionary innovation, even if symbionts were lost secondarily. This leads to the intriguing possibility that symbiosis has played a role in other major evolutionary innovations as well, even if not all extant representatives of such groups still have the symbiotic association. We evaluate this hypothesis for two innovations in termites (Termitoidae, also known informally as Isoptera): i) the role of flagellate gut protist symbionts in the transition to eusociality from cockroach-like ancestors, and ii) the role of non-gut associated symbionts in the transition to 'higher' termites, characterized by the absence of flagellate gut protists. In both cases we identify a crucial role for symbionts, even though in both cases, subsequently, symbionts were lost again in some lineages. We also briefly discuss additional possible examples of symbiogenesis. We conclude that symbiogenesis is more broadly applicable than just for the endosymbiotic origin of eukaryotes and photosynthetic eukaryotes, and may be a useful concept to acknowledge the important role of symbiosis for evolutionary innovation. However, we do not accept Lynn Margulis's view that symbiogenesis will lead to a paradigm shift from neoDarwinism, as the role of symbiosis in evolutionary change can be integrated with existing theory perfectly. (C) 2017 The Authors. Published by Elsevier Ltd.

【 授权许可】

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