RAPID: Recovering at-risk Holocene fossils to test phylogenetic & ecological hypotheses for extinction in crocodiles (Crocodylus) & giant tortoises (Aldabrachelys) of Mada

2014年，来自马达加斯加喀斯特潜水项目的洞穴潜水员意外地在马达加斯加西南部的两个洞穴中发现了一个全新世和现代化石材料的宝库。一个由美国国家科学基金会资助的探险队由阿默斯特的马萨诸塞州大学和马达加斯加的塔那那利佛大学的研究人员领导，进一步探索了水下洞穴，以记录精细的环境变化及其与岛上重大灭绝事件的关系。该项目提供了一个机会，以恢复和记录大量灭绝的鳄鱼和巨龟标本，并记录生态过程的改变如何可能导致马达加斯加巨型动物群落的灭绝和下降的最新模式。动物群的采样和记录将用于正在进行的古代DNA工作，以解决灭绝物种的进化关系，并确定5000年内灭绝的驱动因素。该研究将专门解决关于现代和最近灭绝的马达加斯加鳄鱼和巨龟之间的分类学和系统发育关系的假设。此外，这些集合和相关的地层数据将使我们能够确定精细尺度的时间动态的基因组多样性，饮食和动物群的变化，在这些类群和人类的到来在马达加斯加西南部灭绝前的时期之间的关系。这一完整的沉积系列与以前收集的这些和其他全新世类群在马达加斯加的比较将有助于解释物种组成，丰度和遗传多样性的变化后，人类的到来，并在岛上已知的气候变化的社区。拟议工作的社会影响将包括美国和马达加斯加研究人员共同创造知识。通过有计划的博物馆活动和公开讲座，提供大量的外联和教育机会，确保更多的参与。更广泛地说，该研究促进了美国和马达加斯加学术研究人员和当地利益相关者之间持续的跨学科研究和互动。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

AbstractIn 2014 cave divers from the Madagascar Karst Diving Project unexpectedly identified a treasure trove of Holocene and recent fossil material in two caves in Southwestern Madagascar. An NSF funded expedition led by researchers from the University of Massachusetts in Amherst and the University of Antananarivo in Madagascar further explored the submerged caves to document fine-scale environmental changes and their relationship to major extinction events on the island. This project provides an opportunity to recover and document a large number of specimens of extinct crocodiles and giant tortoises and to document how alteration of ecological processes may have led to recent patterns of extinction and decline among the megafaunal communities of Madagascar. The sampling and documentation of the fauna will be used in ongoing ancient DNA work to resolve the evolutionary relationships of extinct species and to identify drivers of extinction over a period of 5000 years. The research will specifically address hypotheses regarding the taxonomic and phylogenetic relationships between modern and recently extinct Madagascan crocodiles and giant tortoises. Additionally, these collections and associated stratigraphic data will allow us to identify the relationship between fine scale temporal dynamics of genomic diversity, diet and faunal change in these taxa and the arrival of humans in southwestern Madagascar during the pre-extinction period. Comparison of this intact depositional series with previous collections of these and other Holocene taxa across Madagascar will help explain changes in species composition, abundance, and genetic diversity within communities following the arrival of humans and during known climate shifts on the island. Societal impacts of the proposed work will include co-generation of knowledge by US and Malagasy researchers. Additional engagement is ensured through abundant opportunities for outreach and education via planned museum activities and public lectures. More broadly, this research promotes continued interdisciplinary research and interaction among academic researchers and local stakeholders from the U.S. and Madagascar.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.