Figure 1.

Schema showing how changing the distance threshold between species hypotheses (SHs) influences our comprehension of species delimitation and intraspecific variation: (a). Distance threshold between species is set to ≤ 1%. All four individuals belong to different SHs, and the intraspecific variation is zero; (b). The distance threshold is set to ≤ 1.5% and three SHs are delimited. Because the distance between individuals 2 and 3 is less than 1.5%, they fall into the same SH, which has an intraspecific variation of 1.4%. Two other individuals remain distinguished as separate species; (c). The distance between SHs is set to ≤ 2% and now all four individuals belong to a single SH with an intraspecific variation of 2.6%. Some distances are greater than 2%, but these individuals have sister individuals with a distance of less than 2%.