From IO9: a new method for visualising changes in networks have been applied to journal citation data from 7000 journals over the last decade.
The main result: ‘neuroscience’ became its own field sometime during 2003-2005, when citations from molecular & cell biology, neurology, psychology, and a few other disciplines coalesced into one field. It’s also interesting to see just how huge the field of molecular & cell biology is. Remembering this data is based on citations – no wonder those journals have such high impact factors compared to say… journals on hearing etc..
Citation: Rosvall M, Bergstrom CT (2010) Mapping Change in Large Networks. PLoS ONE 5(1): e8694. doi:10.1371/journal.pone.0008694
Read the paper here.