Figure 3 from: Espinasa L, D. Bartolo N, E. Newkirk C (2014) DNA sequences of troglobitic nicoletiid insects support Sierra de El Abra and the Sierra de Guatemala as a single biogeographical area: Implications for Astyanax. Subterranean Biology 13: 35-44. https://doi.org/10.3897/subtbiol.13.7256

Figure 3 - Base pair differences versus estimates of divergence in nicoletiids. Base pair differences in the 16S rRNA fragment is plotted against estimates of divergence times millions of years ago (Mya). Molecular clock calibrating points were extracted from: a populations of Anelpistina musticensis that got separated into different islands when the sea level rose after glacial times 12,000 years ago (Espinasa et al. 2011) b and c species of Prosthecina and d species of Anelpistina from Baja California that got separated from the mainland species when the Gulf of Cortes formed 5 mya (Espinasa et al. 2009) e time when nicoletiids arose from a common ancestor with Lepismatids 302 mya (Regier et al. 2010), and f time when insects arose from a common ancestor with anostraca in the Silurian-Ordovician boundary 427 mya (Gaunt and Miles 2002). The lower arrow indicates the 11–12 bp differences between the Sierra de Guatemala and the Sierra de El Abra Anelpistina populations. Such sequence difference is consistent with a common origin very recently, less than 12,000 years ago, and therefore after the environmental disturbances of the ice age.