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phylogeny_with_beast [2013/06/29 15:28] anniearchambault |
phylogeny_with_beast [2013/09/11 17:30] (current) anniearchambault |
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| - | ====Testing evolutionary hypothesis with BEAST2.0==== | + | ====Dating a node with BEAST2.0==== |
| For details, read http://beast2.cs.auckland.ac.nz/index.php/Main_Page and http://beast2.cs.auckland.ac.nz/index.php/FAQ . | For details, read http://beast2.cs.auckland.ac.nz/index.php/Main_Page and http://beast2.cs.auckland.ac.nz/index.php/FAQ . | ||
| + | For any problem, do not hesitate to browse through the list of questions on the BEAST forum https://groups.google.com/forum/#!forum/beast-users . | ||
| ===Exercise description=== | ===Exercise description=== | ||
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| http://qcbs.ca/wp-content/uploads/2013/06/ProteaFaurea_trnL.txt | http://qcbs.ca/wp-content/uploads/2013/06/ProteaFaurea_trnL.txt | ||
| - | The files include sequences of the ITS and the trnL regions, from 74 species of the //Protea// genus, which comprises a total of 115 species, and the same loci from one specimen of //Faurea//, the sister genus of //Protea//. According to another study, the split leading to //Faurea// and to //Protea// is 28.4 Ma (central 95% range 24.4–32.3 Ma). With an approximate date for this single root node, and the DNA sequences in hand, we will try to answer the question: How old is one of the oldest clade in //Protea//, comprising //P. cryophila, P. lorea, P. pruinosa, P. scabriuscula, P. scolopendrifolia// ? | + | The files include sequences of the ITS and the trnL regions, from 74 species of the //Protea// genus, which comprises a total of 115 species, and the same loci from one specimen of //Faurea//, the sister genus of //Protea//. According to another study, the split leading to //Faurea// and to //Protea// is 28.4 Ma (central 95% range 24.4–32.3 Ma). With an approximate date for this single root node, and the DNA sequences in hand, we will try to answer the question: How old is one of the oldest clade in //Protea//, comprising //P. cryophila, P. pruinosa, P. scabriuscula, P. scolopendrifolia// ? |
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| ===Step by step instructions=== | ===Step by step instructions=== | ||
| - | (Optional, if time allows) Before importing into BEATi, use any phylogenetic program you liked to run an analysis of the sequence datasets provided, to confirm that the 5 species listed above truly group into a clade. | + | (Optional, if time allows) Before importing into BEATi, use any phylogenetic program you liked, to run an analysis of the sequence datasets provided, to confirm that the 5 species listed above truly group into a clade. |
| - | **1** Import the two files in BEAUti, with File/Import Alignment. For each, we will now go over the top panel (Partitions / Tip dates / Site Model / Clock Model / Priors / MCMC), to choose all the options required to answer the question. BEAUti will then create a .xml file readable by the BEAST program. | + | **1** Import the two files in BEAUti, with File/Import Alignment. For each, we will now go over the top panel (Partitions / Tip dates / Site Model / Clock Model / Priors / MCMC), to choose all the required options. BEAUti will then create a .xml file readable by the BEAST program. |
| **2** Tip dates: Nothing is added or modified to this panel | **2** Tip dates: Nothing is added or modified to this panel | ||
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| {{:beast_subs_model1.png?400|Substitution models in BEAUti for ITS}} | {{:beast_subs_model1.png?400|Substitution models in BEAUti for ITS}} | ||
| - | For the trnL, we will choose the model selected by JModelTes2 \\ | + | For the trnL, we will choose the model selected by JModelTest2 \\ |
| + | {{:jmodeltest_seeresults.png?200|best substitution models from jModelTest for trnL}} | ||
| {{:beast_subs_model_trnl.png?400|Substitution models in BEAUti for trnL}} | {{:beast_subs_model_trnl.png?400|Substitution models in BEAUti for trnL}} | ||
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| **5** Setting the Priors \\ | **5** Setting the Priors \\ | ||
| - | This step is the most complicated of the whole process. | + | This step is the **most critical and most complicated** of the whole process. |
| For the Tree prior, we will select the Yule model. Yule models are generally appropriate with sequences from different species, while Coalescent models are for different populations of a same species. Do the same for both partitions (ITS and trnL) | For the Tree prior, we will select the Yule model. Yule models are generally appropriate with sequences from different species, while Coalescent models are for different populations of a same species. Do the same for both partitions (ITS and trnL) | ||
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| For the GammaShape, leave it as it is, Exponential, Mean=1, check estimate. | For the GammaShape, leave it as it is, Exponential, Mean=1, check estimate. | ||
| - | For kappa for ITS, also leave it as it is, LogNormal, M=1, S=1.25 | + | For kappa for ITS, also leave it as is, LogNormal, M=1, S=1.25 |
| We will now add two calibration nodes, to answer the original question. One node will be the root, it will include all taxa (including the single Faurea), and we will set a specific known age to it. The other node will include the 5 species listed above, and we will name this clade "OldClade_ITS" and "OldCladetrnL". Beast will estimate an age for this clade. \\ | We will now add two calibration nodes, to answer the original question. One node will be the root, it will include all taxa (including the single Faurea), and we will set a specific known age to it. The other node will include the 5 species listed above, and we will name this clade "OldClade_ITS" and "OldCladetrnL". Beast will estimate an age for this clade. \\ | ||
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| For the two created sets, check the monophyletic box, select Normal, Mean=28.4, Sigma=2.5, do not check the estimate box. | For the two created sets, check the monophyletic box, select Normal, Mean=28.4, Sigma=2.5, do not check the estimate box. | ||
| - | Create two new taxon sets, for the trnL and the ITS tree, each containing the five species //P. cryophila, P. lorea, P. pruinosa, P. scabriuscula, P. scolopendrifolia//. Label the sets OldClade_ITS and OldClade_trnL. For each set, Select Normal, check the monophyletic box, and add a reasonable number for Mean, Mean=11, check the estimate box, Sigma=1, check estimate. \\ | + | Create two new taxon sets, for the trnL and the ITS tree, each containing the four species //P. cryophila, P. pruinosa, P. scabriuscula, P. scolopendrifolia//. Label the sets OldClade_ITS and OldClade_trnL. For each set, Select Normal, check the monophyletic box, and add a reasonable number for Mean, Mean=11, check the estimate box, Sigma=1, check estimate. \\ |
| {{:beast_taxaset_normal_1.png?400|}} | {{:beast_taxaset_normal_1.png?400|}} | ||
| - | You can notice that new parameters appeared. Leave them as is for now. | + | You can notice that new parameters appeared. Leave them as for the exercise. |
| **6** MCMC \\ | **6** MCMC \\ | ||
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| **8** Run the analysis \\ | **8** Run the analysis \\ | ||
| Save your the BEAUti settings as a .xml file. Open the BEAST program, Load the .xml file, and run the search. When completed, modify the name. This is because for you be able to re-launch an BEAST analysis with the same .xml file. | Save your the BEAUti settings as a .xml file. Open the BEAST program, Load the .xml file, and run the search. When completed, modify the name. This is because for you be able to re-launch an BEAST analysis with the same .xml file. | ||
| + | ++++ Or use this example file | | ||
| + | Here is one xml file: http://qcbs.ca/wp-content/uploads/2013/09/ProteaFaurea_ITS_trnl_test18.xml_.txt | ||
| + | ++++ | ||
| **9** Analyze the results \\ | **9** Analyze the results \\ | ||
| - | Open the program Tracer. Load the newly created .log file. Or load the \\ | + | Open the program Tracer. Load the newly created .log file. \\ |
| Select the two mrcatime(OldClade) values, and look at the Estimates. \\ | Select the two mrcatime(OldClade) values, and look at the Estimates. \\ | ||
| + | Try answer the questions http://qcbs.ca/wp-content/uploads/2013/09/Beast_questions3.pdf \\ | ||
| {{:tracer_mrca_old.png?400|}} | {{:tracer_mrca_old.png?400|}} | ||
| **10** Look at the trees \\ | **10** Look at the trees \\ | ||
| Open the TreeAnnotator program. \\ | Open the TreeAnnotator program. \\ | ||
| - | Burnin (in nb of trees)= 500 \\ | + | Burnin (in nb of trees)= 30000 \\ |
| - | Posterior probability limit=0.5 (a value of 0 will annotate all trees) \\ | + | Posterior probability limit=0.9 (a value of 0 will annotate all trees) \\ |
| Target Tree Type= Maximum clade credibility tree \\ | Target Tree Type= Maximum clade credibility tree \\ | ||
| Node height= Mean heights \\ | Node height= Mean heights \\ | ||
| Choose the trnL input file and give a name for output file. \\ | Choose the trnL input file and give a name for output file. \\ | ||
| + | {{:treeannotator_screen.png?400|}} | ||
| Open the FigTree program \\ | Open the FigTree program \\ | ||
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| Re-root at Faurea, and order nodes, decreasing or increasing at your preference \\ | Re-root at Faurea, and order nodes, decreasing or increasing at your preference \\ | ||
| Check "Node Bars", select "Height_95%_HPD" \\ | Check "Node Bars", select "Height_95%_HPD" \\ | ||
| + | {{:figtree_trnl2.png?400|}} | ||
