I'm trying to get the divergence time of two lineages of a species. I can use two calibration points found in another study. One of them is the mrca of my species and another species in the same genus, the other is the mrca of the genus of the species that I'm studying and it's sister genus. Since my alignment contains both interspecific and intraspecific sequences, I want to use Yule speciation for the whole tree but a coalescent prior for the clade of my species. I've searched up and down and it seems this is possible (e.g. http://europepmc.org/article/PMC/3108604) but I can't figure out how to set up this analysis. Can anyone help me in this regard?