Department of Anthropology, University of Colorado Boulder, Boulder, CO, 80309, USA.
Department of Ecology and Evolution, State University of New York, Stony Brook, NY, 11794, USA.
J Hum Evol. 2019 Aug;133:99-107. doi: 10.1016/j.jhevol.2019.01.003. Epub 2019 Jun 27.
The African savannas that many early hominins occupied likely experienced stark seasonality and contained mosaic habitats (i.e., combinations of woodlands, wetlands, grasslands, etc.). Most would agree that the bulk of dietary calories obtained by taxa such as Australopithecus and Paranthropus came from the consumption of vegetation growing across these landscapes. It is also likely that many early hominins were selective feeders that consumed particular plants/plant parts (e.g., leaves, fruit, storage organs) depending on the habitat and season within which they were foraging. Thus, improving our understanding of how the nutritional properties of potential hominin plant foods growing in modern African savanna ecosystems respond to season and vary by habitat will improve our ability to model early hominin dietary behavior. Here, we present nutritional analyses (crude protein and acid detergent fiber) of plants growing in eastern and southern African savanna habitats across both wet and dry seasons. We find that many assumptions about savanna vegetation are warranted. For instance, plants growing in our woodland habitats have higher average protein/fiber ratios than those growing in our wetland and grassland transects. However, we find that the effects of season and habitat are complex, an example being the unexpectedly higher protein levels we observe in the grasses and sedges growing in our Amboseli wetlands during the dry season. Also, we find significant differences between the vegetation growing in our eastern and southern African field sites, particularly among plants using the C photosynthetic pathway. This may have implications for the differences we see between the stable carbon isotope compositions and dental microwear patterns of eastern and southern African Paranthropus species, despite their shared, highly derived craniodental anatomy.
许多早期人类居住的非洲稀树草原可能经历了明显的季节性变化，并且包含了镶嵌栖息地（即林地、湿地、草原等的组合）。大多数人会同意，像南方古猿和傍人这样的分类群获得的大部分饮食卡路里来自于食用这些景观中生长的植被。此外，许多早期人类可能是选择性食者，根据他们觅食的栖息地和季节，食用特定的植物/植物部分（例如，叶子、水果、储存器官）。因此，提高我们对现代非洲稀树草原生态系统中潜在人类植物食物的营养特性如何响应季节变化以及因栖息地而异的理解，将提高我们模拟早期人类饮食行为的能力。在这里，我们展示了在干湿季节生长在东非和南非稀树草原栖息地的植物的营养分析（粗蛋白和酸性洗涤剂纤维）。我们发现，许多关于稀树草原植被的假设是合理的。例如，生长在我们林地栖息地的植物的平均蛋白质/纤维比高于生长在我们湿地和草原地段的植物。然而，我们发现季节和栖息地的影响是复杂的，例如，在我们安博塞利湿地的旱季，我们观察到草和莎草中的蛋白质水平出乎意料地高。此外，我们发现生长在我们东非和南非野外地点的植被之间存在显著差异，特别是在使用 C 光合作用途径的植物之间。这可能对我们在东非和南非傍人物种的稳定碳同位素组成和牙齿微观磨损模式之间看到的差异产生影响，尽管它们具有共享的、高度衍生的颅面解剖结构。
