skip to main content
Home  /  About  /  Positions Available  /  Postdoctoral Positions  /  Postdoctoral position in stable isotope geochemistry and ecology

Postdoctoral position in stable isotope geochemistry and ecology

Postdoctoral positions in stable isotope geochemistry and ecology

The Tejada Lab ( at the California Institute of Technology is recruiting two postdoctoral scholars to work on projects aligned with our lab's near- and long-term research interests (below). Our lab employs a multiproxy approach, encompassing stable isotope geochemistry, phylogenetics, morphoanatomy, and geo- and biomarkers, to address evolutionary, ecological, and environmental questions in extant and extinct organisms. Leveraging on Caltech's strength of instrument availability and instrument development (e.g., ULTRA, Orbitrap), the lab also aims to develop new methods to retrieve information from currently inaccessible biological materials. The successful candidates will work closely with the PI, as well as with PI collaborators within and outside Caltech, benefiting from multidisciplinary and inclusive lab environments. Experience in stable isotope geochemistry and IRMS instruments, along with robust quantitative and communication skills, are required. The specific postdoctoral projects are as follows:

1) d15N of amino acids using an Orbitrap mas spectrometer: Nitrogen stable isotope ratios of amino acids are powerful indicators of trophic dynamics, but the amount of material needed for derivatization and subsequent combustion in IRMS makes its application to many fossil systems virtually impossible. The successful candidate(s) will develop a novel method to measure d15N from synthetic and naturally sourced amino acids using an Orbitrap mass spectrometer in combination to GC-IRMS methods. Prior work with an Orbitrap is not required, but the applicant is expected to have experience with other IRMS, MS, and/or HPLC systems.

2) Isotopic structure of mammalian communities in equatorial ecosystems: Isotopic structure of tropical ecosystems are still poorly characterized, and generalizations are based on a limited number of localities. The successful candidate will generate new data and work with existing (but unpublished) data from the PI to answer major ecological and evolutionary questions related to differential resource utilization of organisms in analogous tropical ecosystems.

The applicants are expected to have demonstrated interest in one of the specific research topics above, a strong publication record, skills in complementary areas that extend the lab's expertise, and who will both benefit from and add to the community at Caltech. Experience and understanding of stable isotope geochemistry is required. The postdoctoral researchers will have access to cutting-edge facilities in the Tejada Lab and other geochemistry labs in the Division. Opportunities to participate in other ongoing projects in the lab (including field trip expeditions) are also available.

Job responsibilities

In addition to contributing intellectually to the research group, the applicant will primarily:

- Conduct independent research leading to high-impact quality publication(s)

- Perform laboratory chemical work and analytical measurements using IRMS and Orbitrap systems

- Conduct sample collection

- Analyze data and compare model output data


(i) PhD degree (or complete before Summer 2024) in biology, (geo)chemistry, Earth sciences, or other relevant fields

(ii) Prior experience in a geochemistry lab and with stable isotope geochemistry methods

(iii) Strong quantitative skills and demonstrated written and verbal communication skills

(iv) Although different backgrounds will be considered, experience in stable isotope laboratory measurements is particularly desirable

(v) Proficiency in at least one general-purpose programming language is not required but highly valued

Salary is $68,000/year. Scholars are eligible to enroll in Caltech's benefits programs, including health and dental programs.


Review of applications will start April 1st 2024, and the positions will remain opened until filled.


Interested candidates should submit the following to Dr. Julia Tejada ([email protected]):

(i) a cover letter (up to 2 pages) including motivation for applying and research goals

(ii) CV including list of publications

(iii) Contact information (name, position, institution, email) for three references

For questions or more information, please contact Dr. Julia Tejada ([email protected]).

We are an equal opportunity employer and all qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, or national origin, disability status, protected veteran status, or any other characteristic protected by law.