Noreen Hosny ’25


Molecular Biology

Project Title

Analysis of Climate-driven Body-size Changes in the Marine Fossil Record

Presentation Link

View Noreen's Presentation

Certificate(s): Environmental Studies, Visual Arts

As ocean temperatures rise, dissolved oxygen decreases. Yet, marine life requires more oxygen in warmer environments. This inconsistency may shape organisms’ adaptations by causing them to mature at smaller body sizes. I sought to quantify and understand how climate-driven changes to temperature and oxygen affect the body size of benthic (bottom-dwelling) and planktonic (surface-dwelling) foraminifera (single-celled zooplankton). I used temperature and body size data collected from previous literature to calculate and visualize the temperature size effect (TSE) in the program MATLAB for various foraminifera species. We observed very large TSE values and concluded that temperature alone cannot justify these body size changes. I next investigated how the species’ metabolic index (MI) is affected by these changes, since MI accounts for oxygen and temperature simultaneously. I created a trait database documenting the body mass changes and respiration rates and then analyzed these variables in MATLAB to find that oxygen limitation plays a primary role in body size variation. I learned about the pressing effect of climate change on marine biodiversity, which informed my decision to pursue an Environmental Studies certificate. I hope to take environmental science and policy classes to further inform my climate science research.

Internship Year


Project Category

Biodiversity and Conservation


Deutsch Research Group, Department of Geosciences, Princeton University - Princeton, New Jersey


Curtis Deutsch, Professor of Geosciences and the High Meadows Environmental Institute