Organic & Paleoenvironmental Evolution
Research within this group represents an integrated, multidisciplinary approach to the study of interactions between the biosphere and the lithosphere. A unique combination of faculty whose expertise spans the spectrum of spatial and temporal patterns of faunal distribution in modern and ancient systems, and the environments they occupy allow for a broad range of scientific questions concentration on early life and global paleoenvironmental change. The major focuses concentrated on in this department and some of the current research projects are listed below, but interested students should visit faculty web sites for more detail on research interests and current projects.
Paleontology, Paleobiology, Paleoecology
Paleontological studies in the Earth and Planetary Sciences Department focus on both field data and quantitative analysis to address questions ranging from evolutionary paleoecology, to body plan evolution in trilobites.
- The earliest multicellular life-Ediacaran fauna.
- Ecological shifts and community dynamics through the Ordovician Radiation, the Late Devonian Mass Extinction.
- Ecospace utilization of encrusters through the Cenozoic.
- Utilizing geometric morphometrics as a tool for delineating microevolutionary patterns in trilobites
- Paleozoic paleogeography of the Himalayan region
- Development of trilobite body-plan
- Stratigraphic and geochemical record of the biosphere across the Pre-Cambrian-Cambrian boundary.
- Integration of biostratigraphic sequencing and cladistic analysis of faunas
- Improving the resolving power of Paleozoic time scales by computer sequencing of hundreds of localities and thousands of events.
Biogeography, Landscape Ecology and Conservation Biology
The forests and shrublands of southern California provide an excellent laboratory for numerous studies addressing questions concerning anthropogenic effects on the flora and fauna at a variety of scales. Faculty and student researchers combine field observations with remote sensing and computer modeling.
- Fire regimes and the effects of fire suppression on the size and distribution of wildfires
- Computer models of long-term dynamics of fire-modulated patch mosaics
- Alien plant invasion of California shrublands and desert scrub communities
- Habitat fragmentation and connectivity
- Vegetation ordination and wildlife-habitat relationships with GIS
Stratigraphic studies at UCR integrate aspects of classic stratigraphy, paleontology sedimentology, geomorphology and computer science to address a range of research questions at locations around the world. Current topics of research include:
- Empirical scaling laws for rates of stratigraphic processes
- Numerical stratigraphy as a tool to quantify gaps and time averaging in the stratigraphic record
- Bio- and lithostratigraphy of the Cambrian system throughout the Himalaya towards understanding of the recent uplift and erosional history of the Himalayan mountains
- High-resolution biostratigraphic records of graptolites and conodonts of the Ordovician and Silurian
- Stratigraphic constraint of Neoproterozoic glacial events in Death Valley, Namibia, Australia, and Oman.
Sedimentary Geochemistry and Organic Geochemistry
This research investigates the biogeochemistry of both ancient and modern systems utilizing a number of geochemical, biological and sedimentological techniques.
- Using molecular lipid biomarkers, inorganic geochemical proxies (such as reactive Fe speciation, Mo and other redox-sensitive transition metal contents) and stable isotopes ( 13C, 15N, 34S, 18O) to record major episodes of environmental and biotic change through Earth history. One particular focus is the progressive oxygenation of the biosphere in the Proterozoic leading to the first appearance of animals.
- Co-evolution of aquatic environments and microbial community structure (bacteria, archaea and eukaryotes) over geological time.
- Understanding microbial, chemical and thermal processing (diagenesis and catagenesis) of sedimentary organic matter leading to petroleum, coal and natural gas generation.
- Development of analytical strategies for facilitating oil-source correlations in petroleum exploration and understanding basin charging of petroleum fluids.
- Discriminating abiogenic (Fischer Tropsch synthesis in hydrothermal settings, meteorite input) from biogenic organic matter inputs preserved in the Archean rock record using molecular and compound-specific 13C patterns.
- Investigating organic synthesis and preservation in the interstellar medium and on other planetary bodies (such as the icy moons, Europa and Enceladus) and developing the astrobiological search for chemical biosignatures.