Background

A major challenge in astrobiology is that extraterrestrial life could look very different from the life we are familiar with on Earth, especially at the biochemical level. To address this problem, an agnostic biosignature is needed, which is a characteristic or feature of life that does not directly rely on the biological molecules that are found in organisms on Earth. Recently, allometric scaling was proposed as a biosignature in combination with a computational model for resource concentration, consumption, and biomass production in microbial ecosystems. Allometric scaling laws are relationships between physiological and ecological components that scale with organism size, like the famous result that metabolic rate scales with an organism’s body mass by an exponent of ¾. Ecosystems are crucial organizations of biological components and their interactions on Earth, and it is possible that extraterrestrial life would exhibit the same kind of organization. While this model attempts to mathematically simulate multiple microbial populations living together in an ecosystem, their coexistence is currently transient and unstable. We wish to reveal whether the current model can successfully demonstrate the same key properties as living microbial ecosystems, particularly biodiversity and stability.

Research Goals

The team working on this project will uncover cases where coexistence among multiple microbial species is stable in this model. The team will (1) read and understand the original literature for this model, including the past versions that did not yet incorporate allometric scaling laws, (2) become familiar with the existing code in Python and Julia for simulating microbial ecosystems, (3) investigate existing parameters of the model that will influence coexistence among multiple species (4) conduct computational experiments to see whether coexistence is possible given the current paramenters, and (5) observe the effects of coexistence on the non-living resource concentrations.

Skills Needed

Foundational understanding of biology, ecology, and differential equations; basic scientific programming skills; past experience with Python or Julia preferred.

Skills Gained

Students who complete this research will develop a strong understanding of the applications and usefulness of differential equations models for biological systems. They will become proficient in scientific programming and running numerical simulations using Python and Julia, while also receiving an introduction to a small area of contemporary astrobiology research.