This article describes a simple tool to display geophylogenies on web maps including Google Maps and OpenStreetMap. The tool reads a NEXUS format file that includes geographic information, and outputs a GeoJSON format file that can be displayed in a web map application.
From the introduction (with footnotes omitted):
The increasing number of georeferenced sequences in GenBank [ftnt omitted] and the growth of DNA barcoding [ftnt omitted] means that the raw material to create geophylogenies [ftnt omitted] is readily available. However, constructing visualisations of phylogenies and geography together can be tedious. Several early efforts at visualising geophylogenies focussed on using existing GIS software [ftnt omitted], or tools such as Google Earth [ftnt omitted]. While the 3D visualisations enabled by Google Earth are engaging, it’s not clear that they are easy to interpret. Another tool, GenGIS [ftnt omitted], supports 2D visualisations where the phylogeny is drawn flat on the map, avoiding some of the problems of Google Earth visualisations. However, like Google Earth, GenGIS requires the user to download and install additional software on their computer.
By comparison, web maps such as Google Maps [ftnt omitted] are becoming ubiquitous and work in most modern web browsers. They support displaying user-supplied data, including geometrical information encoded in formats such as GeoJSON, making them a light weight alternative to 3D geophylogeny viewers. This paper describes a tool that makes use of the GeoJSON format and the capabilities of web maps to create quick and simple visualisations of geophylogenies.
Whether you are interested in geophylogenies or in the use of GeoJSON, this is a post for you.