CAREER: Persistent vertebrate communities in deep time and the great Triassic-Jurassic vertebrate transition

点击翻译按钮获取中文摘要

A major goal in ecology is to understand how communities respond to minor and major environmental changes over both short (seasons to decades) and long (thousands to millions of years) timescales. It is clear that some communities fair better than others, and it appears that some communities persist for millions of years. This project combines ecological tools for studying living communities with tools used to study extinct communities that can only be reconstructed using the fossil record in order to understand if and how communities persist over long timescales. This project aims to characterize and reconstruct vertebrate communities in the last 20 million years of the Triassic Period (252-200 million years ago) prior to the end-Triassic mass extinction. Those Triassic vertebrate communities are important for understanding communities of living vertebrates because they appear to be static during both quick and gradual climatic changes. Studying these communities will help answer: What makes a community successful during times of short and long-term environmental changes? Are the survivors of great changes a product of those earlier successful communities? These questions are being addressed through new fossils and measurements of the geological data associated with them, reanalyzing previously discovered fossils, and model-based approaches to characterizing the interactions of community members over millions of years of geologic time. Research is being integrated with educational activities at local, regional, and national levels, and graduate and undergraduate students and interested volunteers are being trained. An experiential K-12 teacher field school is taking place in the National Park system, and teaching kits are being built to demonstrate the importance of the fossil record to our understanding of our natural world.‘At what timescales do communities remain similar or relatively unchanged?’ is a fundamental question that unites biologists, ecologists, and paleontologists, but the varied approaches to answering this question from each scientific community has limited our ability to understand and predict the effect of disturbances on our living communities in light of increasing species extinctions, climate change, and human disturbance. The ultimate goal of this 5-year CAREER proposal is to develop an innovative program that critically evaluates community persistence in the fossil record by integrating quantitative measurements of communities derived from neontological studies, ecological modeling, and paleontological studies. This study provides an explicit framework for testing whether a paleocommunity (=fossil assemblage) is persistent using taphonomic approaches, a suite of quantitative characteristics, new analytical tools (e.g., modeling food webs, likelihood models), and sensitivity and resampling techniques. The research team is analyzing and assimilating taxonomic (e.g., clade-specific) and functional (e.g., ecomorphology) diversity, diet, and phylogenetic community structure in terrestrial vertebrate paleocommunities across 10s of millions of years from localities that span the Triassic-Jurassic boundary. The outcomes of this study include: 1) enhancement of our ability to understand the interplay of taxonomic and functional diversity, macroevolution, and community structure; 2) elucidation of the transformation of Triassic to Jurassic paleocommunities; and 3) insights into the functional roles of the survivors before and after a broad scale perturbation. Macroevolution, ecology, and environmental change in deep time are combined into teaching, student mentorship, and broad public programs at local, regional, and national levels. An all-immersive Discoveries in Geosciences (DIG) Field School is training K-12 teachers in the scientific process of a historical science, and this program is producing paleontology-inspired activities (e.g., 3D printable fossils) for K-12 students at the national level.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.