Doctoral Dissertation Research: Ecology, biology, and coexistence among multiple species of human ancestors

东非遗址的人类化石记录差异太大，不能归因于一个原始人物种。有人提出，多达五个人种--博伊西拟人、能人、鲁道夫人、尔加斯特人和直立人--在空间、时间和所消耗的食物资源上存在重叠。该项目确定了东非博伊塞人和早期人在更新世(约2.5百万年之后)之间竞争的程度和类型。了解早期人是如何在我们属历史的这个关键早期阶段对与其他物种的竞争做出反应的，可以让我们更好地欣赏我们自己的解剖、行为和可塑性。这项研究对生态学和生物学研究也有更广泛的影响。性状置换是导致密切相关物种共存的因素之一，它影响着生态群落的结构，有助于推动物种形成和生物多样性的分布。该项目还与美国和国际上的教育专家一起制定了教案，并支持对一名女性学者的培训。研究人员使用3D几何形态测量(GM)形状变化分析来测试物种间的竞争是否影响了我们人类属的进化，以及这种竞争是否有任何显著的形态影响。传统智慧认为，随着时间的推移，早期人通过竞争性排斥导致了P.boisei的灭绝。然而，该项目应用了更新的3D GM形状变化分析方法来测试生态位现实性，这是一种在古人类学中通常不被考虑的竞争假说。研究人员使用博伊塞人和早期人超过一百万年的磨牙形态证据来调查任何物种间竞争的性质和潜在原因。这项研究的结果可能会提供这些种群之间随着时间的推移而竞争的证据，并通过展示非祖先原始人可能如何影响我们自己的祖先谱系的轨迹来改变以前关于人的例外论的叙述。这一奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Variation in the human fossil record from sites in eastern Africa is too great to be attributed to one hominin species. It has been suggested that up to five hominin species – Paranthropus boisei, Homo habilis, Homo rudolfensis, Homo ergaster, and Homo erectus ¬– overlapped in space, time and in the dietary resources consumed. This project identifies the extent and type of competition between eastern African P. boisei and early Homo during the Pleistocene (after c. 2.5 mya). Understanding how early Homo responded to competition with other species at this critical early stage in the history of our genus allows us to better appreciate our own anatomy, behavior and plasticity. This study also has broader implications for ecological and biological research. Character displacement, which is one of the factors that enables the coexistence of closely related species, influences the structure of ecological communities, and helps drive speciation and the distribution of biodiversity. The project also creates lesson plans with education experts in the United States and internationally and supports the training of a woman scholar.The researchers use 3D geometric morphometric (GM) shape-change analysis to test whether interspecific competition influenced the evolution of our genus Homo through time, and whether there were any significant morphological effects of this competition. Conventional wisdom suggested that early Homo led to the extinction of P. boisei over time through competitive exclusion. However, this project applies an updated 3D GM shape-change analysis methodology to test for ecological niche incumbency, a type of competition hypothesis that has not typically been considered in paleoanthropology. The investigators use molar morphological evidence from over a million years in P. boisei and early Homo to investigate the nature and potential causes of any interspecific competition. The results of this study may provide evidence of competition between these genera through time and transform previous narratives of Homo exceptionalism by showing how a non-ancestral hominin may have influenced the trajectory of our own ancestral lineage.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.