Dear users,
I tried to use MrBayes 3.2.6 (MPI) to date a fixed phylogeny. I set the priors as uniform with lower and/or upper bounds. But some of the resulting ages (including 95% HPD) present lower than the lower bound of priors. I paste my commands and the resulting chronogram afterward. Hope someone can help me. Thanks!
===== MB commands (passing data block) =====
[data set]
[tree topology]
begin trees;
tree huichong = [&R] ((((((((((((((RAP_Hysterothylacium_fabri,RAP_Hysterothylacium_spn),RAP_Hysterothylacium_aduncum),RAP_Hysterothylacium_reliquens),((RAP_Raphidascaris_longispicula,RAP_Raphidascaris_lophii),RAP_Hysterothylacium_longilabrum)),((RAP_Hysterothylacium_liparis,RAP_Hysterothylacium_sinense),RAP_Hysterothylacium_thalassini)),RAP_Raphidascaroides_nipponensis),(((((RAP_Raphidascaroides_moraveci,RAP_Raphidascaroides_brasiliensis),RAP_Hysterothylacium_pelagicum),RAP_Maricostula_tetrapteri),(RAP_Hysterothylacium_deardorffoverstreetorum,RAP_Raphidascaris_acus)),(((RAP_Hysterothylacium_amoyense,RAP_Hysterothylacium_zhoushanense),RAP_Goezia_pelagia),RAP_Iheringascaris_inquies))),(((((ASC_Baylisascaris_schroederi,ASC_Baylisascaris_ailuri),ASC_Baylisascaris_transfuga),(ASC_Baylisascaris_columnaris,ASC_Baylisascaris_procyonis)),((ASC_Ascaris_lumbricoides,ASC_Ascaris_suum),ASC_Parascaris_equorum)),ASC_Toxascaris_leonina)),((((ACA_Mawsonascaris_spn,ACA_Mawsonascaris_myliobatum),ACA_Mawsonascaris_zhoui),(ACA_Acanthocheilus_rotundatus,ACA_Pseudanisakis_rajae)),(((ASC_Toxocara_vitulorum,ASC_Toxocara_cati),ASC_Toxocara_canis),(ASC_Porrocaecum_depressum,ASC_Porrocaecum_reticulatum)))),(((((((((ANI_Anisakis_berlandi,ANI_Anisakis_simplex),ANI_Anisakis_pegreffii),ANI_Anisakis_ziphidarum),ANI_Anisakis_typica),((ANI_Anisakis_brevispiculata,ANI_Anisakis_paggiae),ANI_Anisakis_physeteris)),ANI_Terranova_caballeroi),((ANI_Pseudoterranova_azarasi,ANI_Pseudoterranova_cattani),ANI_Pseudoterranova_decipiens)),ANI_Pulchrascaris_chiloscyllii),(((((ANI_Contracaecum_ogmorhini,ANI_Contracaecum_rudolphii),ANI_Contracaecum_bioccai),ANI_Contracaecum_multipapillatum),ANI_Contracaecum_microcephalum),((ANI_Contracaecum_osculatum,ANI_Phocascaris_cystophorae),ANI_Contracaecum_radiatum)))),(((HETC_Dujardinascaris_gigantea,HETC_Ortleppascaris_sinensis),HETC_Krefftascaris_sharpiloi),HETC_Heterocheilus_tunicatus)),OGCOS_Oxyascaris_sp),OGCOS_Cruzia_americana),OGHETK_Ascaridia_galli);
end;
begin mrbayes;
charset ITS = 1-1382;
charset 28S = 1383-2152;
charset 18S = 2153-3908;
charset COICOII = 3909-4948 4949-5540;
charset 12S = 5541-6069;
partition matrices = 5: ITS, 28S, 18S, COICOII, 12S;
set partition = matrices;
lset applyto=(1) nst=6 rates=invgamma;
lset applyto=(2) nst=2 rates=invgamma;
lset applyto=(3) nst=2 rates=invgamma;
prset applyto=(3) statefreqpr=fixed(equal);
lset applyto=(4) nst=2 rates=invgamma;
lset applyto=(5) nst=6 rates=invgamma;
prset applyto=(all) ratepr=variable;
unlink statefreq=(all) revmat=(all) shape=(all) pinvar=(all) tratio=(all);
[all the constrained clades are monophyletic nodes in the tree above]
constraint RAP = RAP_Goezia_pelagia RAP_Hysterothylacium_aduncum RAP_Hysterothylacium_amoyense RAP_Hysterothylacium_deardorffoverstreetorum RAP_Hysterothylacium_fabri RAP_Hysterothylacium_liparis RAP_Hysterothylacium_longilabrum RAP_Hysterothylacium_pelagicum RAP_Hysterothylacium_reliquens RAP_Hysterothylacium_sinense RAP_Hysterothylacium_spn RAP_Hysterothylacium_thalassini RAP_Hysterothylacium_zhoushanense RAP_Iheringascaris_inquies RAP_Maricostula_tetrapteri RAP_Raphidascaris_acus RAP_Raphidascaris_longispicula RAP_Raphidascaris_lophii RAP_Raphidascaroides_brasiliensis RAP_Raphidascaroides_moraveci RAP_Raphidascaroides_nipponensis;
constraint ACA_Mawsonascaris = ACA_Mawsonascaris_myliobatum ACA_Mawsonascaris_spn ACA_Mawsonascaris_zhoui;
constraint ANI_Anisakis = ANI_Anisakis_berlandi ANI_Anisakis_brevispiculata ANI_Anisakis_paggiae ANI_Anisakis_pegreffii ANI_Anisakis_physeteris ANI_Anisakis_simplex ANI_Anisakis_typica ANI_Anisakis_ziphidarum;
constraint ANI_Pseudoterranova = ANI_Pseudoterranova_azarasi ANI_Pseudoterranova_cattani ANI_Pseudoterranova_decipiens;
calibrate
RAP = unif(151.2,250.0)
ACA_Mawsonascaris = unif(170.3,1E4) [**NOTE: I used 1E4 instead of unlimited upper bound. The resulting age of this node (MRCA) is only ~30 Mya!**]
ANI_Anisakis = unif(33.9,52.4)
ANI_Pseudoterranova = unif(28.5,50)
;
prset brlenspr=clock:uniform;
prset treeagepr = unif(0,541);
prset nodeagepr=calibrated;
prset ratepr=variable topologypr=fixed(huichong);
prset clockratepr=lognorm(-7,0.6);
prset clockvarpr=igr;
prset igrvarpr=exp(10);
set usebeagle=yes beagledevice=cpu beagleprecision=double;
set beaglescaling=dynamic beaglesse=yes;
mcmc ngen= 10000000 printfreq=1000 samplefreq=1000 nruns=4 nchains=5 savebrlens=yes;
end;
======== resulting tree (red box show the clade with wrong estimates)
![image](https://cloud.githubusercontent.com/assets/10971017/21979729/2ec10e54-dc1b-11e6-887d-9e9cd9dbfd23.png)