[supernovae]

The "conventional simple tree" is just a depiction of data put into visual representation easy for humans to understand.

On the lineage of species, the actual heritage and relationship through evolution is more of an acyclic graph. We just have species that we know fill the gap between other species enough to know that a tree is the simplest way to depict evolution over billions of years, just like a tree may depict a family genealogy or family tree but even then we know its not all linear because humans have married between families and been incestuous at times.