Writing systems are cultural replicators whose evolution has never been studied quantitatively at global scale. We compile the Global Script Database (GSD): 300 writing and notation systems, 50 binary structural characters, and 259 phylogenetic edges spanning 5,400 years. Applying four methods -- phenetics, cladistics, Bayesian inference, and neural network clustering -- we find that scripts exhibit a detectable molecular clock. The best-fitting model (Mk+Gamma strict clock) yields a substitution rate of q = 0.226 substitutions/character/millennium (95% CI: 0.034-1.22; Delta BIC = -4.1 versus relaxed clock; Delta BIC = -1,364.7 versus Mk without rate variation). Political interventions break this clock: deviation from expected divergence times correlates with intervention intensity (Spearman rho = 0.556, p < 10^{-4}), and per-character rate analysis reveals that intervention selectively rewrites deep structural features rather than merely accelerating change (rate profile correlation rho = 0.320). We identify 30 major script replacement events and rank their destructive impact. A ceiling effect suppresses independent invention wherever writing already exists (Fisher's exact OR = 0.054, p < 10^{-6}), and colonial contact predicts script extinction (Cox HR = 5.25, p = 0.0006). The Spanish Empire extinguished the most scripts (6 of 12 contacted, 50%), followed by the Empire of Japan (3 of 9, 33.3%). Feature coding was validated by inter-rater reliability testing with two independent human coders (Cohen's kappa = 0.877; human-LLM kappa = 0.929; Fleiss' kappa = 0.911).

翻译：书写系统是文化复制因子，其演化从未在全球尺度上得到定量研究。我们构建了全球文字数据库（GSD）：涵盖300种文字与记谱系统、50个二元结构特征、以及跨越5400年的259条系统发育边。运用四种方法——表型学、分支系统学、贝叶斯推断和神经网络聚类——我们发现文字系统具有可检测的分子钟。最优拟合模型（Mk+Gamma严格时钟）得出的替代速率为q=0.226替代/字符/千年（95%置信区间：0.034-1.22；与宽松时钟相比的Delta BIC=-4.1；与无速率变异Mk模型相比的Delta BIC=-1364.7）。政治干预打破这一时钟：偏离预期分化时间与干预强度相关（斯皮尔曼相关系数ρ=0.556，p<10^{-4}），且每字符速率分析显示，干预并非简单加速变化，而是选择性重写深层结构特征（速率谱相关ρ=0.320）。我们识别出30次主要文字替代事件，并对其破坏性影响进行排序。天花板效应抑制了已有书写文化中的独立发明（费希尔精确检验比值比OR=0.054，p<10^{-6}），而殖民接触预示着文字消亡（Cox比例风险模型HR=5.25，p=0.0006）。西班牙帝国毁灭的文字数量最多（接触的12种中消失6种，占50%），其次是日本帝国（接触的9种中消失3种，占33.3%）。特征编码经两位独立人类编码者的信度检验验证（Cohen's kappa=0.877；人类-大语言模型kappa=0.929；Fleiss' kappa=0.911）。