Data from: How to date a molecular phylogeny: Comparison of effective priors between node calibration and FBD

Time-calibrating a phylogenetic tree is a fundamental step in phylogenetic
inference, as it allows the study of macroevolutionary processes such as
lineage diversification, trait evolution, and historical biogeography. To
this end, the fossilized-birth-death (FBD) process, a stochastic process
that coherently integrates fossils into phylogenies, is increasingly used
as an alternative to traditional ad hoc node-calibration
densities. However, the effective prior distribution on node ages induced
by the FBD has never been investigated before, hindering an informed
choice between the two approaches. Here, we analyze two empirical datasets
(crocodylians and fireflies) by applying several models of
time-calibration, including traditional node calibrations and FBD. We show
that the effective node age priors induced by the FBD process in the
absence of morphological data are comparable to those induced by uniform
node calibrations with minimum equal to the age of the calibrating fossil,
and maximum equal to the maximum age of the tree. Our exploration sheds
light into how paleontological information is translated to node ages by
the FBD process, and suggests that node calibration approaches remain an
important alternative when the fossil record of the studied group is
scarce and other prior information can be used to devise informative
calibration densities.