Optimal conditions represent the golden standard in experimental biology studies. Yet, the definition of ‘optimal’ is rather vague and optimal conditions are non-existent in nature, which operates at suboptimal conditions. This apparent paradox has implications in both curiosity-driven research that seeks answers to fundamental biological questions and in preclinical research that aims to identify drugs for real-life pathologies and patients.

Laboratory tests in biology are typically performed under what is perceived as optimal conditions. For example, cells in culture are maintained at 37 °C, with glucose at a concentration of around or just above 5.5 mM, and abundant growth factors and nutrients. Similarly, mouse experiments are performed with animals of same sex that are caged together, frequently in groups of five individuals. Photoperiod is steady throughout the experiment and usually alternates between 12 h light and 12 h dark, temperature is around 25 °C, water is abundant, and food is provided ad libitum throughout the study and has also been selected to be optimal for the specific animal species. Depending on the specific goals of the experiment, if any of these conditions are interrogated, they do change by a systematic manner, but the experimental set-up remains the same. One can test the effects of low temperature or different diets for example, but again, the rest of the conditions are maintained stable, and importantly optimal, which is considered as the prerequisite to extract meaningful conclusions.

最佳条件代表了实验生物学研究的黄金标准。然而，“最佳”的定义相当模糊，并且自然界中不存在最佳条件，而是在次优条件下运行。这种明显的悖论对于寻求基本生物学问题答案的好奇心驱动的研究和旨在为现实生活中的病理学和患者识别药物的临床前研究都有影响。

生物学实验室测试通常在被认为是最佳的条件下进行。例如，培养中的细胞维持在37°C，葡萄糖浓度约为或略高于5.5 mM，以及丰富的生长因子和营养物质。同样，小鼠实验是用同性别的动物进行的，这些动物被关在笼子里，通常是五只为一组。整个实验过程中光周期稳定，通常在 12 小时光照和 12 小时黑暗之间交替，温度约为 25 °C，水充足，在整个研究过程中随意提供食物，并且也选择了最适合特定动物的食物物种。根据实验的具体目标，如果询问任何这些条件，它们确实会以系统的方式发生变化，但实验设置保持不变。例如，我们可以测试低温或不同饮食的影响，但同样，其余条件保持稳定，而且重要的是最佳，这被认为是得出有意义的结论的先决条件。