Two axes in one

An intelligent (nice, informative and compact) way of breaking up an axis without the need of doubling the axis in two lines. 

Figure 1. Sample- and individual-based rarefaction and accumulation curves. Accumulation curves (jagged curves) represent a single ordering of individuals (solid-line, jagged curve) or samples (openline, jagged curve), as they are successively pooled.  [...]

Reference Gotelli, N.J. and Colwell, R.C. (2001) Quantifying biodiversity: procedures and pitfalls in the measurement and comparison of species richness. Ecology Letters 4: 379–391. (paper link)

Input courtesy of Dr. Conchita Alonso