A strict molecular clock was assumed given the shallow levels of divergence, with a mitochondrial mean rate of 1.52%% divergence per million years, with a standard deviation of 0.5 % divergence, based on mtDNA calibrations from other squamates [ 69].
was assigned a normally distributed prior with a mean of 48 Ma and a standard deviation of 0.3, and the divergence between the subgenera Chamaetia and Vetrix was assigned an exponential distribution prior with a mean of 1 and offset (hard bound constraint) of 23 Ma.
In comparison to results obtained without correction or with the standard "divergence source terms," our approach seems to yield more robust schemes with significantly smaller divergence errors.
Although generally allowing global conservation of kinetic energy, it has the drawback of being roughly twice as expensive as standard divergence or advective forms alone.
When modeling flux densities as solution variables, it is argued that solenoidal function spaces should be used, rather than the standard divergence-conforming function spaces; this assertion is supported by the results.
Second, we ran three sets of analyses using the fastest (2.28%/my – [ 75]) and slowest (0.9%/my – [ 76]) insect mitochondrial substitution rates, as well as a standard invertebrate mitochondrial divergence rate of 1.5%/my [ 77] as the rough median.
A standard threshold of 2% divergence for identifying species has been proposed [ 61].
In all of these implementations, strict divergence is a standard assumption of the multispecies coalescent.
We adopted a standard two-step procedure to estimate divergence times.
t Denotes divergence time (in years) between the two populations assuming a standard mutation rate of 5.56×10-4, whereas t est_mut denotes divergence time (in years) assuming a mutation rate of 3.00×10-4, reflectheg the mutation rate estimates obtained using DIYABC.
The K2P distance matrix showed a relatively high overall mean interspecific divergence of 18.3% with a standard error of 1.3%.
