Herbivore Niche Differentiation and the Intensification of Competition in African Savannahs

在今天的非洲，萨凡纳环境表现出高草食动物的多样性和狭窄的生态位分区，反映在一个良好的层次的摄食偏好和身体大小。在旱季尤其如此，因为此时资源很少，饮食重叠最少。该项目旨在追踪东非上新世和更新世化石记录中萨凡纳羚羊（牛科）生态位划分的演变。许多关于非洲新近纪记录的研究都集中在进化与全球气候变化之间的相关性上，但这项研究旨在量化竞争性生物相互作用的强度。这是通过一个基于特征的方法，即草食动物的饮食特征多样性预计将随着时间的推移，分支变得更加专业化。这可能是由于食物竞争的增加而发生的，也许是长期环境变化导致资源减少的结果。为了验证这一想法，该项目将开发一个大型的形态特征数据库，利用分子和形态数据构建系统发育框架，并研究来自埃塞俄比亚、肯尼亚和坦桑尼亚的许多新的和未发表的化石组合。

In Africa today, savannah environments exhibit high herbivore diversity and narrow niche partitioning, reflected in a fine gradation of feeding preferences and body sizes. This is particularly true during the dry season, when resources are low and dietary overlap is at a minimum. This project seeks to trace the evolution of niche partitioning among savannah antelopes (Bovidae) in the Pliocene and Pleistocene fossil record of eastern Africa. Many studies of the African Neogene record have focused on correlations between evolution and global climate change, but this study aims to quantify the intensity of competitive biotic interactions through time. This is done through a trait-based approach, whereby herbivore dietary trait diversity is expected to increase over time as clades became more specialized. This would have occurred in response to increased dietary competition, perhaps as a result of decreasing resources caused by long-term environmental change. In order to test this idea, the project will develop a large morphological trait database, construct a phylogenetic framework using both molecular and morphological data, and study many new and unpublished fossil assemblages from Ethiopia, Kenya, and Tanzania.