Fig. 4

Authors contribution to different areas. Each column represents the 99%-quantile distribution of the number of different scientific areas that an author has published in during the corresponding temporal snapshot. Each icon represents, through its color, the density of authors having published in a given number of areas during a given temporal snapshot. The figure clearly shows that over time authors have increasingly started to publish in more and more scientific areas, i.e. they are becoming more and more multidisciplinary. The radius and the color of the circles along the time axis represent the volume of authors that have published during the corresponding temporal snapshot, for reference