Abstract
Since chemical abundances are inherited between generations of stars, we use
them to trace the evolutionary history of our Galaxy. We present a robust
methodology for creating a phylogenetic tree, a biological tool used for
centuries to study heritability. Combining our phylogeny with information on
stellar ages and dynamical properties, we reconstruct the shared history of 78
stars in the Solar Neighbourhood. The branching pattern in our tree supports a
scenario in which the thick disk is an ancestral population of the thin disk.
The transition from thick to thin disk shows an anomaly, which we attribute to
a star formation burst. Our tree shows a further signature of the variability
in stars similar to the Sun, perhaps linked to a minor star formation
enhancement creating our Solar System. In this paper, we demonstrate the
immense potential of a phylogenetic perspective and interdisciplinary
collaboration, where with borrowed techniques from biology we can study key
processes that have contributed to the evolution of the Milky Way.