Julia Tejada

Ge 104. Introduction to Geobiology. 9 units (3-0-6); second term, 2026-27. Prerequisites: instructor's permission. Lectures about the interaction and coevolution of life and Earth surface environments. We will cover essential concepts and major outstanding questions in the field of geobiology, and introduce common approaches to solving these problems. Topics will include biological fractionation of stable isotopes; history and operation of the carbon and sulfur cycles; evolution of oxygenic photosynthesis; biomineralization; mass extinctions; analyzing biodiversity data; constructing simple mathematical models constrained by isotope mass balance; working with public databases of genetic information; phlyogenetic techniques; microbial and molecular evolution.
Instructor: Tejada

Ge 11 b. Introduction to Earth and Planetary Sciences: Earth and the Biosphere. 9 units (3-3-3); second term, 2026-27. Prerequisites: Ch 1 a. Systematic introduction to the origin and evolution of life and its impact on the oceans, atmosphere, and climate of Earth. Topics covered include ancient Earth surface environments and the rise of atmospheric oxygen. Microbial and molecular evolution, photosynthesis, genes as fossils. Banded iron stones, microbial mats, stromatolites, and global glaciation. Biological fractionation of stable isotopes. Numerical calibration of the geological timescale, the Cambrian explosion, mass extinctions, and human evolution. The course usually includes one major field trip and laboratory studies of rocks, fossils, and geological processes. Although Ge 11 abcd is designed as a sequence, any one term may be taken as a standalone course. Biologists are particularly welcome.
Instructor: Tejada

Ge/Bi 244. Seminar in Paleobiology: The Amazon. 6 units (3-0-3); first term, 2026-27. This seminar examines the geology and biology of one of Earth’s most biodiverse and dynamic regions: the Amazon rainforest. Through student-led discussions, we will trace the evolution of the Amazon Basin across geologic time. We will analyze the fossil record to reconstruct past ecosystems, evaluate the Amazon’s role in the modern Earth system, and critically assess the challenges of conducting paleobiological research in tropical environments. Discussions will be Socratic in nature, with the instructor guiding deeper inquiry rather than delivering lectures. Evaluation is based on participation, quality of intellectual contributions, and demonstrated mastery of the material.  Enrollment is limited to 10 students. Participants will be selected at the start of the term based on background, interests, and commitment to active engagement throughout the course.
Instructor: Tejada

Ge 104. Introduction to Geobiology. 9 units (3-0-6); second term, 2025-26. Prerequisites: instructor's permission. Lectures about the interaction and coevolution of life and Earth surface environments. We will cover essential concepts and major outstanding questions in the field of geobiology, and introduce common approaches to solving these problems. Topics will include biological fractionation of stable isotopes; history and operation of the carbon and sulfur cycles; evolution of oxygenic photosynthesis; biomineralization; mass extinctions; analyzing biodiversity data; constructing simple mathematical models constrained by isotope mass balance; working with public databases of genetic information; phlyogenetic techniques; microbial and molecular evolution.
Instructor: Tejada

Ge 11 b. Introduction to Earth and Planetary Sciences: Earth and the Biosphere. 9 units (3-3-3); second term, 2025-26. Prerequisites: Ch 1 a. Systematic introduction to the origin and evolution of life and its impact on the oceans, atmosphere, and climate of Earth. Topics covered include ancient Earth surface environments and the rise of atmospheric oxygen. Microbial and molecular evolution, photosynthesis, genes as fossils. Banded iron stones, microbial mats, stromatolites, and global glaciation. Biological fractionation of stable isotopes. Numerical calibration of the geological timescale, the Cambrian explosion, mass extinctions, and human evolution. The course usually includes one major field trip and laboratory studies of rocks, fossils, and geological processes. Although Ge 11 abcd is designed as a sequence, any one term may be taken as a standalone course. Biologists are particularly welcome.
Instructor: Tejada

Ge/Bi 244. Paleobiology Seminar. 6 units (3-0-3); first term, 2025-26. Critical reviews and discussion of classic investigations and current research in paleoecology, evolution, and biogeochemistry.
Instructor: Tejada

Ge/Bi/ESE/CE 249. Stable Isotopes: Ecological and Environmental Applications. 9 units (3-3-3); first term, 2025-26. An introduction to various stable isotopes systems and their extensive applications in ecological, evolutionary, and environmental research. Topics covered include uses of stable isotopes in plant and animal ecology, hydrological systems, reconstruction of past climates, cultural development, and forensics. The class includes lectures and occasional lab sessions.
Instructor: Tejada