ERIS applies one of the principles of Darwin’s Theory of Evolution – descent with modification – to cosmic evolution.
With ERIS we aim to reconstruct the evolution of galaxies like the Milky Way using the phylogenetic trees, which are already extensively used in other evolutionary studies for biology. Since trees are mathematical structures and graphs, with ERIS we are consolidating an interdisciplinary collaboration between astronomers, biologists and mathematicians, in order to achieve our goal. We focus on reconstructing the evolution of the Milky Way, because this is the best laboratory but we aim at moving to extragalactic astronomy, by building and interpreting phylogenetic trees that are appropriate for astronomical data. To do so, we simulate the evolution of galaxies, where we know their shared history. We also use observed data, which allow us to learn to explore the Milky Way, and ultimately help us to constrain the theory of galaxy evolution.
The key to chemical evolution in galaxies is the well known fact that massive stars synthesize chemical elements in their interiors, and at the end of their lives, they pollute the interstellar clouds from which new stars form. Chemically processed gas is what one generation of stars inherits from the previous one(s) and is the key observable for us to build the phylogenetic trees. Our strength is the fact that we know relatively well what elements are produced in which type of stars, and how much of each of them. The challenge is the fact that a galaxy is an open system: gas comes from outside all the time, diluting the existing one. Also, different generations of stars contribute to the pollution of the same interstellar material. Therefore, the problem is manifold and intricate, just like the biological evolution of species.
The primary objective of ERIS is to propose a new field of research. There are other two goals which are relevant to achieving the first objective. The first one is the training of young scientists in this field of research. We generate an environment in which students and young postdocs actively interact and collaborate with the members of our team. The second one is the impact of interdisciplinary sciences in society. We are working on targeted schools to help them in their development of critical thinking skills.