Clark Kevin B
Biosystems. 2010 Jan;99(1):27-41. doi: 10.1016/j.biosystems.2009.08.005. Epub 2009 Aug 15.
Learning to reciprocate socially valued actions, such as cheating and cooperation, marks evolutionary advances in animal intelligence thought unequalled by even colonial microbes known to secure respective individual or group fitness tradeoffs through genetic and epigenetic processes. However, solitary ciliates, unique among microbes for their emulation of simple Hebbian-like learning contingent upon feedback between behavioral output and vibration-activated mechanosensitive Ca(2+) channels, might be the best candidates to learn to reciprocate necessary preconjugant touches perceived during complex 'courtship rituals'. Testing this hypothesis here with mock social trials involving an ambiguous vibration source, the large heterotrich ciliate Spirostomum ambiguum showed it can indeed learn to modify emitted signals about mating fitness to encourage paired reproduction. Ciliates, improving their signaling expertise with each felt vibration, grouped serial escape strategies gesturing opposite 'courting' assurances of playing 'harder to get' or 'easier to get' into separate, topologically invariant computational networks. Stored strategies formed patterns of action or heuristics with which ciliates performed fast, quantum-like distributed modular searches to guide future replies of specific fitness content. Heuristic-guided searches helped initial inferior repliers, ciliates with high initial reproductive costs, learn to sensitize their behavioral output and opportunistically compete with presumptive mating 'rivals' advertising higher quality fitness. Whereas, initial superior repliers, ciliates with low initial reproductive costs, learned with the aid of heuristics to habituate their behavioral output and sacrifice net reproductive payoffs to cooperate with presumptive 'suitors', a kind of learned altruism only before attributed to animal social intelligences. The present findings confirm that ciliates are highly competent decision makers capable of achieving paired fitness goals through learning.
学会对诸如欺骗与合作等具有社会价值的行为做出回应，标志着动物智力的进化进步，这种进步即使在已知通过基因和表观遗传过程确保个体或群体适应性权衡的群居微生物中也被认为是无与伦比的。然而，单细胞纤毛虫在微生物中独树一帜，它们模仿简单的类似赫布学习方式，这种学习取决于行为输出与振动激活的机械敏感钙通道之间的反馈，可能是学会对复杂“求偶仪式”中感知到的必要交配前接触做出回应的最佳候选者。在此，通过涉及模糊振动源的模拟社交试验来检验这一假设，大型异毛纤毛虫模糊旋口虫表明它确实能够学会修改关于交配适应性的发出信号，以鼓励配对繁殖。纤毛虫随着每次感受到的振动提高其信号传递技能，将连续的逃避策略分组，这些策略表示相反的“求偶”保证，即表现得“更难追求”或“更容易追求”，形成了单独的、拓扑不变的计算网络。存储的策略形成了行动模式或启发式方法，纤毛虫利用这些方法进行快速的、类似量子的分布式模块化搜索，以指导未来具有特定适应性内容的回应。启发式引导搜索帮助最初处于劣势的回应者，即初始繁殖成本高的纤毛虫，学会使其行为输出敏感化，并 opportunistically 与宣传更高质量适应性的假定交配“对手”竞争。而最初处于优势的回应者，即初始繁殖成本低的纤毛虫，借助启发式方法学会使其行为输出习惯化，并牺牲净繁殖收益以与假定的“追求者”合作，这是一种以前仅归因于动物社会智力的习得性利他行为。目前的研究结果证实，纤毛虫是高度能干的决策者，能够通过学习实现配对适应性目标。
原文中“opportunistically”这个词在中文语境中较难找到完全对应的准确词汇，这里保留英文以便更准确传达原文意思。
