The middle chapters in Earth's history, roughly 1.8 to 0.8 billion years ago, were defined by remarkable stability in generally low but persistent oxygen levels in the ocean and atmosphere and stifled development of early organisms for a billion years. How and when this cycle was broken are among the central unanswered questions in the history of life on Earth. The eventual rise to higher oxygen levels and ultimately the appearance of animals correspond generally with history's most extreme climatic events and mountain building episodes, and the timing and cause-and-effect relationships among all these events and processes are frontiers ripe for study. To this end, we will construct an unusually comprehensive chemical data set for rocks from Australia and Arctic Canada deposited directly within the transition between the stable 'boring' billion and the major milestones that followed.
The onset of global-scale glaciation 0.7 to 0.8 billion years ago is without question one of the most dramatic environmental transitions in Earth history, and the generally synchronous radiation of eukaryotic organisms, with greater complexity than their microbial ancestors, and the emergence of animals are among the most remarkable evolutionary events in the long history of life. The proposed multidisciplinary team will illuminate the timing of these key events and their likely links to Earth's oxygenation, while probing the cause-and-effect relationships among biological innovation, oxygen, and the onset of global-scale glaciation. The study's full range of impacts will reach far beyond the intrinsic scientific merit, including high-level research opportunities for the diverse undergraduate populations at all three institutions. We will also reach out into the community through sponsorship of science fair projects and through many different contributions to the new Riverside STEM Academy, including organization of a lecture series that will bring prominent scientists and engineers into the school. The study also includes plans for collaborative mentoring of graduate students, including student exchanges, and is an important step in the early careers of two new professors.
