Figure 1.

Overall scheme of a phylotastic system. The user (upper left) experiences a phylotastic system as a piece of software that returns a phylogeny in response to a query consisting of a list of taxa (and possibly other qualifiers). The user’s point of access to the system is a client program or controller that invokes various operations to access (and transform) the information needed to satisfy the user’s query. The response ultimately depends on information available from name-banks, source trees, and calibrations (right). There are many ways to implement such a system. In the approach described here, it is a system of loosely coupled components that uses web services to exchange information using common standards.