Collaborative Research: Gateway to North America--the Great American Biotic Interchange (GABI) in Mexico and Origin of C4 Grassland

合作研究：北美门户——墨西哥大美洲生物交汇处（GABI）与C4草原起源

• 批准号: 1949613
• 负责人: Jack Tseng
• 金额: $ 5.32万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1949613&HistoricalAwards=false
• 关键词: Collaborative; Research; Gateway; North; America

Historical patterns of animal movements between the Americas are crucial to understanding current ecosystems and natural resources. The Great American Biotic Interchange (GABI) is a highly significant historical event of land animal movements between North and South America, triggered by the emergence of the continent-bridging Isthmus of Panama three million years ago. Isthmus formation substantially modified global ocean circulation, climate, and American ecosystems. Large animals such as giant ground sloths, armored glyptodonts, and terror birds moved northward and became an integral part of North American Ice Age ecosystems. North American elephant-like gomphotheres, horses, deer, camels, and carnivorans expanded into South America and triggered the most recent large mass extinction of native animals on that continent. A joint U.S.-Mexico team will investigate the timing and magnitude of these events in central Mexico, a critical gap in knowledge for GABI vertebrate and plant fossils. Integration of long-term fossil records with paleoenvironmental analysis will permit a more detailed reconstruction of the ecosystem reorganization events that led to today’s biodiversity patterns in the Americas. Broader impacts of the project include the development of Spanish and English museum exhibits and digital media, and research training opportunities for students from groups that are underrepresented in STEM fields.A team of vertebrate paleontologists, structural geologist, functional morphologist, phytolith botanist, and stable isotope geochemist will conduct field investigations in central Mexico to establish an integrated regional chronological framework using radiometric dates, fossil mammal biostratigraphy, and magnetostratigraphy to document succession of GABI immigrants. They will assess associated vegetation change using phytoliths and quantify relationships between herbivore diets and C4 vegetation origin, regional climate, and hydrological cycles in North America using isotope analysis of mammalian dental enamel and paleosol carbonates. Broad inter-continental mammal distributional patterns will be contextualized using network analysis to quantify deep-time biogeographic connectivity. Findings will be used to test hypotheses regarding phylogenetic relationships of key immigrant taxa, timing and delay in dispersal to high latitude regions, and climatic and environmental implications of regional C4 grassland expansion.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.

美洲之间动物迁徙的历史模式对于了解当前的生态系统和自然资源至关重要。大美洲生物互换（GABI）是北美和南美之间陆地动物迁徙的一个非常重要的历史事件，由三百万年前连接大陆的巴拿马地峡的出现引发。地峡的形成极大地改变了全球海洋环流、气候和美国生态系统。巨型地懒、铠甲雕齿兽和恐鸟等大型动物向北迁移，成为北美冰河时代生态系统不可分割的一部分。 北美象形的嵌齿象、马、鹿、骆驼和食肉动物扩展到南美洲，并引发了该大陆最近的本土动物大规模灭绝。 美国-墨西哥联合小组将调查墨西哥中部这些事件的发生时间和规模，这是 GABI 脊椎动物和植物化石知识的一个关键空白。将长期化石记录与古环境分析相结合，将能够更详细地重建导致美洲今天生物多样性模式的生态系统重组事件。该项目的更广泛影响包括开发西班牙语和英语博物馆展品和数字媒体，以及为 STEM 领域代表性不足的群体的学生提供研究培训机会。由脊椎动物古生物学家、结构地质学家、功能形态学家、植硅体植物学家和稳定同位素地球化学家组成的团队将在墨西哥中部进行实地调查，利用辐射日期、化石建立一个综合的区域年代框架。 哺乳动物生物地层学和磁地层学来记录 GABI 移民的演替。他们将使用植硅体评估相关植被变化，并使用哺乳动物牙釉质和古土壤碳酸盐的同位素分析来量化北美草食动物饮食与 C4 植被起源、区域气候和水文循环之间的关系。将使用网络分析来量化广泛的洲际哺乳动物分布模式，以量化深度生物地理连通性。研究结果将用于检验有关关键移民类群的系统发育关系、向高纬度地区扩散的时间和延迟，以及区域 C4 草原扩张对气候和环境影响的假设。该奖项反映了 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。