If we decide that we want to maximize biodiversity, then the phylogenetic patterns produced by systematists give us a way to prioritize areas based upon the diversity they contain. In order to maximize diversity, it makes sense to try to preserve groups from throughout the tree of life, rather than large numbers from one branch. In this way we will tend to preserve a wider array of features that have potential use for humans, though their uses may presently be unknown, but it does mean that we have to know something about the relationships of the organisms involved. Systematics provides independent evidence for patterns of geological change . The continents have not always held the positions on the Earth that they do today, nor have they been the same size and shape.
Geologists use data from the Earth itself to reconstruct past arrangements of land masses.
However, there is an independent source of data for such reconstructions, which lies in the current distribution of taxa when viewed in the light of their relationships. When continents fragment, the taxa that live on them record this change, since the separated taxa will then have their own history, but share the common ancestor that was once continuously distributed. By constructing organismal phylogenies and mapping on current distributions of taxa, and doing this for many groups, general patterns emerge that may best be explained by historical geological events. Systematists and systematic collections provide identification services and documentation of identity . Another crucial role for systematists is that of identification specialists.