Acerenza Luis
System Biology Laboratory, Faculty of Sciences, Universidad de la República, Iguá 4225, 11400, Montevideo, Uruguay.
J Mol Evol. 2016 Mar;82(2-3):117-27. doi: 10.1007/s00239-016-9730-3. Epub 2016 Feb 26.
Understanding evolutionary trajectories remains a difficult task. This is because natural evolutionary processes are simultaneously affected by various types of constraints acting at the different levels of biological organization. Of particular importance are constraints where correlated changes occur in opposite directions, called trade-offs. Here we review and classify the main evolutionary constraints and trade-offs, operating at all levels of trait hierarchy. Special attention is given to life history trade-offs and the conflict between the survival and reproduction components of fitness. Cellular mechanisms underlying fitness trade-offs are described. At the metabolic level, a linear trade-off between growth and flux variability was found, employing bacterial genome-scale metabolic reconstructions. Its analysis indicates that flux variability can be considered as the currency of fitness. This currency is used for fitness transfer between fitness components during adaptations. Finally, a discussion is made regarding the constraints which limit the increase in the amount of fitness currency during evolution, suggesting that occupancy constraints are probably the main restrictions.
理解进化轨迹仍然是一项艰巨的任务。这是因为自然进化过程同时受到作用于生物组织不同层次的各种类型限制的影响。特别重要的是那些在相反方向上发生相关变化的限制，即所谓的权衡。在这里，我们回顾并分类了在性状层次结构的所有层次上起作用的主要进化限制和权衡。特别关注生活史权衡以及适合度的生存和繁殖成分之间的冲突。描述了适合度权衡背后的细胞机制。在代谢水平上，利用细菌基因组规模的代谢重建发现了生长与通量变异性之间的线性权衡。其分析表明，通量变异性可被视为适合度的货币。这种货币在适应过程中用于适合度成分之间的适合度转移。最后，讨论了限制进化过程中适合度货币数量增加的限制因素，表明占用限制可能是主要限制。
