1. An organism cannot be fully optimized for all tasks that are needed for its survival because of the existence of intrinsic trade‐offs among those tasks. It was recently proposed that an economics‐originated theory, the Pareto theory, is a general theory explaining the rules of phenotypic evolution under such trade‐offs. To date, many phenotype datasets have been argued to fit the Pareto theory based on a statistical method named the t‐ratio test.
2. Here, we show that this test suffers a serious defect in that general phenotype data can be wrongly concluded to fit the Pareto theory with a very high false‐positive rate and that the claim that the Pareto theory is a general theory should definitely be considered with caution. This is because the t‐ratio test assumes that all phenotypic traits are independent of one another, but this assumption does not hold true—different traits of organisms have usually been affected by the same phylogenetic history and are thus typically not independent.
3. We developed the flipping t‐ratio test to accurately test the Pareto theory by considering phylogenetic background as well as artefacts that can be induced during dimensionality reduction. Using this improved method, we confirm that the phenotype data analysed in previous studies, including the well‐known Darwin's ground finch dataset, no longer support the Pareto theory.
4. We hope that the flipping t‐ratio test will contribute to examining which phenotype datasets truly fit the Pareto theory and understanding how diverse phenotypes evolve in natural ecosystems.

中文翻译：

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翻转t比率检验：系统研究对帕累托表型进化的理论的评估

1. 由于这些任务之间存在内在的取舍，因此无法针对其生存所需的所有任务完全优化生物。最近有人提出，起源于经济学的理论，即帕累托理论，是解释这种折衷下表型进化规则的一般理论。迄今为止，已经有许多表型数据集被认为符合基于t检验的统计方法的帕累托理论。
2. 在这里，我们表明该测试遭受了严重的缺陷，因为可以错误地得出一般表型数据以使帕累托理论具有很高的假阳性率，并且肯定应该考虑认为帕累托理论是一个通用理论。警告。这是因为t比率检验假设所有表型性状都是彼此独立的，但是这种假设并不成立，因为不同的生物性状通常都受到相同的系统发生历史的影响，因此通常不是独立的。
3. 我们开发了翻转t比检验，通过考虑系统发育背景以及降维过程中可能引起的伪像，来准确检验帕累托理论。使用这种改进的方法，我们确认先前研究中分析的表型数据，包括著名的达尔文的地面雀科数据集，不再支持帕累托理论。
4. 我们希望翻转t比率检验将有助于检查哪些表型数据集真正符合帕累托理论，并了解自然生态系统中各种表型如何演化。