The Millennium Nucleus ERIS, recognized for its groundbreaking approach to galactic phylogenetics, was recently featured in the documentary program “The Sky at Night”, aired by the UK’s BBC Four channel. In the episode, professor and host Chris Lintott traveled to the University of Cambridge to interview astronomer Payel Das and anthropologist Robert Foley, both members of ERIS since its inception.
Galactic phylogenetics is an emerging discipline that combines tools from evolutionary biology, mathematics, and astronomy to understand the formation and evolution of galaxies. Inspired by the principles of Charles Darwin, this field integrates techniques such as chemical abundance analysis and galactic evolution models, opening new possibilities to study the universe from an interdisciplinary perspective. The Millennium Nucleus ERIS has been a pioneer in this field, leading research that merges science and the humanities.
This innovative approach not only seeks to unravel the history of galaxies, but also to establish deep connections between seemingly distant disciplines. Thanks to the work of the Millennium Nucleus ERIS, models have been developed that allow scientists to trace galactic “family trees,” offering an evolutionary view of the cosmos similar to the one Darwin applied to terrestrial species. This interdisciplinary perspective is transforming our understanding of the universe, positioning ERIS as a global reference in this field.
“Chemical elements are special because they evolve in a way that follows the process of ‘descent with modification,’ which underlies evolutionary processes beyond galaxies (for example, the living beings on our planet). It is the stars—formed from clouds of gas and dust—that process new chemical elements in their cores and then release them into the interstellar medium, driving the chemical evolution of a galaxy. The chemical distribution, therefore, depends on how many stars have formed throughout a galaxy’s history, and that depends on how the galaxy has managed to retain or acquire more gas to form the clouds that give birth to stars.” explains Paula Jofré, Director of ERIS.
Robert Foley, Leverhulme Emeritus Professor of Human Evolution at the University of Cambridge, highlighted how his connection with the ERIS project emerged through an interdisciplinary collaboration.
“I met Paula Jofré when she was a postdoctoral researcher at Cambridge and a member of King’s College. I’m an evolutionary anthropologist and biologist, and on one occasion I gave a talk about how we build evolutionary trees (phylogenies) in biology. After the talk, we discussed whether it was possible to use these same techniques to reconstruct the history of stars. Since then, we’ve collaborated—first in Cambridge and later through ERIS.”, remarks Foley.
Foley emphasized the relevance of the project's interdisciplinary approach:
“The ERIS project is a major challenge, as it combines biological methods with astrophysics. The challenge was to see whether the way stars ‘evolve’ could meet the necessary conditions to apply phylogenetic methods, and ERIS’s work has shown that, although it is complex, it is possible.”
The legacy of ERIS
The work of the nucleus has been significant not only in scientific terms, but also in how it has fostered international collaboration—a crucial aspect for the advancement of its research. The complexity of the project has required cooperation with experts outside of Chile, which has helped raise the team's global profile and attract both national and international talent. Paula Jofré comments on the importance of this collaboration: “In a project as complex as ERIS, you need very specific tools and knowledge that no single scientist can possess entirely. That’s why we’ve had to collaborate with those who contribute this expertise and who are passionate about helping us solve our interdisciplinary challenge. We’ve found a group of key people for the advancement of our project who simply happen to be outside the country.”
Looking ahead, the ERIS team sees great opportunities in developing phylogenetic tools specifically designed for astronomy. Although their work as a Millennium Nucleus concludes at the end of 2024, the work that remains promises to revolutionize the way we understand the evolution of galaxies. As pioneers in establishing galactic phylogenetics within the scientific community, this group has opened a new line of research that combines innovative approaches and traditionally distant disciplines.