Data for: Hidden diversity: Comparative functional morphology of humans and other species

Gastrointestinal (GI) morphology plays an important role in nutrition, health, and epidemiology, yet limited data on gastrointestinal variation have been collected since 1885. Here we demonstrate that students can collect reliable data sets on gut morphology; when they do, they reveal greater morphological variation for some structures in the GI than has been documented in the published literature. We discuss trait variability both within and among species, and the implications of that variability for evolution and epidemiology. Our results show that morphological variation in the GI tract is associated with each organ’s role in food processing. For example, the length of many structures was found to vary significantly with feeding strategy. Within species, the variability illustrated by the coefficients of variation suggests that selective constraints may vary with function. Within humans, we detected significant correlations between the various lengths of the liver and appendix (p = 0..., We measured the length of internal organs to the nearest 0.01 cm using sliding calipers, spreading calipers, ruler tape, rulers, and string. We also measured the body length of each specimen and calculated the volume of the liver using the formula for a cone. , All data were analyzed in the R environment.胃肠道（Gastrointestinal, GI）形态学在营养、健康与流行病学领域均具有重要意义，但自1885年以来，关于胃肠道变异的相关数据收集工作始终较为匮乏。本研究证实，学生群体可采集到可靠的胃肠道形态学数据集；通过该数据集，我们发现部分胃肠道结构的形态学变异程度远超已发表文献中的记载。我们探讨了物种内部及物种间的性状变异情况，以及该变异对演化与流行病学的启示。研究结果表明，胃肠道的形态学变异与各器官在食物加工过程中的功能息息相关。例如，诸多结构的长度会随摄食策略的不同出现显著差异。在物种层面，通过变异系数所展现的变异程度提示，选择约束可能随功能的不同而存在差异。在人类群体中，我们检测到肝脏与阑尾的各项长度指标间存在显著相关性（p = 0...）。我们使用滑动卡尺（sliding calipers）、展距卡尺（spreading calipers）、卷尺、直尺与细绳，将内脏器官的长度测量精度控制至0.01厘米。同时，我们测量了每一份标本的体长，并利用圆锥体积公式计算肝脏体积。所有数据分析工作均在R编程环境中完成。