Data from: Appearance of an early closure of the Isthmus of Panama is the product of biased inclusion of data in the metaanalysis

In their PNAS article “Biological evidence supports an early and complex
emergence of the Isthmus of Panama,” Bacon et al. (1 -
http://dx.doi.org/10.1073/pnas.1423853112) use data from molecular
comparisons of terrestrial and marine organisms taken from the literature
to estimate dates of rate shifts in migration. One of their conclusions is
that “events separating marine organisms in the Atlantic and Pacific
oceans [occurred] at ca. 23 and 7 Ma” (1). The authors base this
conclusion on two kinds of molecular dating: (i) 31 dates from phylogenies
with evolutionary rates calibrated from fossils at one or more nodes, and
(ii) 52 dates from mitochondrial divergence between sister species on
either side of the Isthmus taken from the review by Lessios (2) (note:
complete data are available from the Dryad Digital Repository at
http://dx.doi.org/10.5061/dryad.6m653). For the latter, divergence was
converted to time by assuming a mitochondrial DNA divergence rate of 2%
per million years. Unfortunately, Bacon et al.’s metaanalysis of
separations of marine organisms contains unexplained omissions of data and
mistakes.