This Millenium Nucleus ERIS applies one of the principles of Darwin’s Theory of Evolution -descent with modification to the evolution of our Galaxy. Phylogenetic trees are used in biology to represent ancestors and descendants of species. In ERIS, the evolutionary relationship between stars comes from how they synthesize new elements in their interiors and pollute the interstellar medium with freshly produced material. Massive stars will die and pollute the environment, from which a new generation of stars will be born, inheriting that chemical composition. This is an oversimplification of how heritability would work in stars, given that a Galaxy has complex processes that could affect its chemical pattern. ERIS is establishing phylogenetic studies of stars as a new research field, trying to understand all the intricate details of the history of the Milky Way.
