A Multi-proxy palaeo-environmental investigation of Middle Pleistocene Vietnam: Implications for hominin adaptation, distribution, and mobility

人们对东南亚大陆人类进化的复杂性仍知之甚少；然而，化石和遗传分析表明，它是中晚更新世适应、物种形成和混合的关键区域，人们普遍认为这与环境条件有关。该项目将采用多种方法来研究人类与环境的关系，重点是来自越南北部的考古、地质和动物数据——这是一个在这些争论中代表性不足的地区。具体来说，它将评估热带森林和动物对人类构成障碍，是区域进化的主要驱动力的断言。MSEA地区的古人类进化是在环境变化的背景下进行的，该地区考古记录的特征具有明显的时空差异。人们普遍认为，在智人到来之前，广阔的热带森林和被提出的剑龙-龙足类动物群（一系列动物物种似乎在更新世中晚期居住在这些热带森林中）作为一种生态屏障，限制和塑造了人类环境（Ciochon 2010）。然而，一项详细的审查至少在两个方面对这种断言提出了质疑：中更新世人工制品和古人类牙列已被自信地与森林典型动物遗骸相关联（例如Liu et al. 2013）；而剑龙-无尾足动物区系复合体——作为一个单一的实体来讨论——通常由来自不同环境的物种组成（例如Dennell 2009）。为了解决这个问题，我的目标是通过将越南北部作为一个有限的案例研究来评估环境条件在多大程度上影响了中更新世MSEA中人类的流动性和适应性。该地区有几个已确认的和潜在的古人类遗址，并发现了一些物种不确定的古人类化石；然而，与邻近的中国南方成功的中更新世研究相比，它仍然被忽视。通过对考古、地质和动物记录的详细研究和比较，并进一步与MSEA周围其他地点的数据进行比较，该项目旨在识别和研究与古人类遗址有强烈关联的生态环境变量，并建立这些变量随时间变化的模型。由此，将有可能产生时间生态变化的地理插图，并检查已确定的人类活动的交叉点。识别这些变量并了解它们之间的相互作用将以一种有意义和可测试的方式推进我们对MSEA中古人类生态局限性的理解。事实上，两个重要的测试将通过模型的能力来增强对古人类遗址的预测，以及识别异域物种形成的驱动因素（地理分离的差异）和混合区域（不同谱系之间成功的杂交）的潜力。

The complexity of human evolution in Mainland Southeast Asia (MSEA) remains poorly understood; yet fossil and genetic analyses suggest it was a key area of Middle to Late Pleistocene adaptation, speciation and admixture, widely thought to be linked to environmental conditions. This project will employ multiple methods to examine the hominin-environment relationship, with a focus on archaeological, geological, and faunal data from Northern Vietnam - an area under-represented in these debates. Specifically, it will evaluate the assertion that tropical forests and fauna presented barriers to hominins and were major drivers of regional evolution.Hominin evolution in MSEA is set against a backdrop of environmental changes, and significant spatial and temporal variation is evident in the character of the archaeological record of the region. It is generally thought that the vast tropical forests and the proposed Stegodon-Ailuropoda faunal complex (a collection of faunal species appearing to have inhabited these tropical forests throughout the Middle to Late Pleistocene), acted as an ecological barrier which restricted and shaped hominin environments prior to the arrival of Homo sapiens (Ciochon 2010). A detailed review, however, questions such an assertion on at least two fronts: Middle Pleistocene artefacts and hominin dentition have been confidently identified in association with forest-typical faunal remains (e.g. Liu et al. 2013); and the Stegodon-Ailuropoda faunal complex - discussed as a single entity - often consists of species from distinct environs (e.g. Dennell 2009). To resolve this issue, my aim is to evaluate the extent to which environmental conditions shaped hominin mobility and adaptation in Middle Pleistocene MSEA, by focusing on northern Vietnam as a limited case study. This region has several confirmed and potential hominin sites as well as yielding several hominid fossils of indeterminate species; yet it remains neglected compared to a successful Middle Pleistocene research in neighbouring southern China. By comprehensively studying and comparing the archaeological, geological and faunal records in detail, and further comparing the data with other sites around MSEA, the project aims to identify and study variables in the ecotopes which exhibit strong associations with hominin sites, and model changes in these over time. From this, it will be possible to produce a geographical vignette of temporal ecological change and examine the intersections with identified hominin activity. Identifying these variables and understanding their interaction will advance our understanding of the ecological limitations of hominins in MSEA in a meaningful and testable way. Indeed, two important tests will come through the model's capacity to enhance prediction for hominin sites, and the potential to identify drivers of allopatric speciation (divergence by geographic separation) and areas of admixture (successful interbreeding between distinct lineages).