Gradual evolution of the 'whole' defined by the keyword “self-organization” from 1990 to 2009 (a). For each 5-year time slice (red circles), we choose the 10 most prolific authors (green circles) and the 10 most used references (pink circles) and keywords (blue circles). Authors, keywords or references are linked to the 5-year time slice in which they appear.
The figure shows that, although most entities (authors, keywords or references) change through time, each time slice inherits something from its predecessor. For example, in the 90s, scientists interlocked their definition of self-organization through "neural networks", while in the 2000s, "growth" of "nanostructures" became a more powerful link.
