Exobiology and Evolutionary Biology

PI: Chapman, Mary

The goal of NASA’s Exobiology and Evolutionary Biology program is to understand the origin, evolution, distribution, and future of life in the Universe, which includes research on the Evolution of Advanced Life on Earth with an explicitly expressed interest in terrestrial mass extinction events. In other words, understanding the causes of terrestrial mass extinctions are an explicit research goal of this NASA program. The loss of species at the end-Triassic (201 Ma) now is referred to routinely as one of the “big five” mass extinctions on Earth; however, the cause of the end-Triassic extinctions is unknown. This proposal requests funding for 2 very specific tasks that can decipher the relative roles of endogenic (Earth-based) and exogenic (extraterrestrial) processes in end-Triassic mass extinction. Task 1: Investigating Causes Of Widespread Wildfire And Associated Reptile, Early Dinosaur, and Amphibian Deaths in the Upper Triassic. The objectives of this task are to (1) establish that bolide impact shocked quartz (with PDFs) occurs at a known wildfire horizon and (2) attempt to find out the lateral extent of the wildfire in order to test the importance of catatrophic impact as a kill mechanism during the end Triassic. Task 2: Investigating the Triassic-Jurassic Boundary time zone of the Lower Moenave in Nevada and Utah. The objectives of this task are to (1) to determine whether the spherules in Nevada are cosmogenic and (2) attempt to find out whether these same types of spherules occur (at another likely accumulation area, in Utah) at the TJB boundary. Methods include field work by the PI to gather samples, private laboratory time (to create rock thin section viewable under a microscope and to perform tests and analyses), and petrographic (microscope) work and publication writing of results by the
PI.