Villarreal Luis P, Witzany Guenther
Center for Virus Research, Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, 92697, USA.
J Mol Evol. 2015 Jun;80(5-6):305-18. doi: 10.1007/s00239-015-9683-y. Epub 2015 May 27.
In the early 1970s, Manfred Eigen and colleagues developed the quasispecies model (qs) for the population-based origin of RNAs representing the early genetic code. The Eigen idea is basically that a halo of mutants is generated by error-prone replication around the master fittest type which will behave similarly as a biological population. But almost from the start, very interesting and unexpected observations were made regarding competition versus co-operation which suggested more complex interactions. It thus became increasingly clear that although viruses functioned similar to biological species, their behavior was much more complex than the original theory could explain, especially adaptation without changing the consensus involving minority populations. With respect to the origin of natural codes, meaning, and code-use in interactions (communication), it also became clear that individual fittest type-based mechanisms were likewise unable to explain the origin of natural codes such as the genetic code with their context- and consortia-dependence (pragmatic nature). This, instead, required the participation of groups of agents competent in the code and able to edit code because natural codes do not code themselves. Three lines of inquiry, experimental virology, quasispecies theory, and the study of natural codes converged to indicate that consortia of co-operative RNA agents such as viruses must be involved in the fitness of RNA and its involvement in communication, i.e., code-competent interactions. We called this co-operative form quasispecies consortia (qs-c). They are the essential agents that constitute the possibility of evolution of biological group identity. Finally, the basic interactional motifs for the emergence of group identity, communication, and co-operation-together with its opposing functions-are explained by the "Gangen" hypothesis.
20世纪70年代初,曼弗雷德·艾根及其同事开发了准种模型(qs),用于解释代表早期遗传密码的RNA基于群体的起源。艾根的基本观点是,围绕最适应的主类型进行易出错复制会产生一群突变体,它们的行为类似于生物群体。但几乎从一开始,就有关于竞争与合作的非常有趣且意想不到的观察结果,这表明存在更复杂的相互作用。因此,越来越明显的是,尽管病毒的功能类似于生物物种,但其行为比原理论所能解释的要复杂得多,尤其是在不改变涉及少数群体的共识的情况下的适应。关于自然密码的起源、意义以及在相互作用(交流)中的密码使用,同样明显的是,基于个体最适应类型的机制同样无法解释自然密码(如遗传密码)的起源,因为它们具有上下文和群体依赖性(实用性质)。相反,这需要有能力使用密码并能够编辑密码的主体群体的参与,因为自然密码本身不会编码。实验病毒学、准种理论和自然密码研究这三条探究路线汇聚在一起,表明诸如病毒之类的合作RNA主体群体必定参与了RNA的适应性及其在交流(即有密码能力的相互作用)中的参与。我们将这种合作形式称为准种群体(qs - c)。它们是构成生物群体身份进化可能性的基本主体。最后,“冈根”假说解释了群体身份、交流和合作出现的基本相互作用基序及其相反功能。