Although if you want to get get technical, even evolutionary relationships are only trees if you throw out some of the information that doesn't fit the tree. It

Although if you want to get get technical, even evolutionary relationships are only trees if you throw out some of the information that doesn't fit the tree. It's truer to speak of phylogenetic networks that can take into account things such as horizontal transfer of genes and recombination. https://en.wikipedia.org/wiki/Phylogenetic_network https://en.wikipedia.org/wiki/Phylogenetic_network