I constructed a phylogenetic tree with MEGA 7.0 by using bootstrap (1000 replicates). But the final tree obtained lacked a scale bar, though it is there in the normal tree. What could be the possible explanation?
You are probably looking at the "bootstrap consensus tree". Because the consensus tree summarizes the information of 1000 different trees, each with its own branch lengths and topology, branch lengths cannot be calculated and this information is lost in the consensus tree. MEGA7 shows the original tree, with the internal branches labelled with the corresponding bootstrap values, in a different tab.
In the phylogenetic tree view window, you can click on VIEW - SHOW / HIDE menu. On the menu there are options show taxon label, taxon marker, Stat / frequency, branch Length, and Scale Bar
Hello. Thanks for the reply. I checked the same, however found that the scale bar option is deactivated in case of bootstrap tree!
I had a similar issue whereby a scale bar was absent from my phylogenetic tree and MEGA7 didn't allow me to add one. The problem was that I inserted two new sequences to the tree but did not align all sequences again using ClustalW before constructing a phylogenetic tree, which prevented the scale bar from being added. Hope this helps!
I have the same problem, lack of scale bar issue. I used MP to make a phylogenetic tree in MEGA5 and MEGA10. 50 bootstraps were compared. Scale bar option is deactivated but when I read a paper they have made a scale bar on the tree, which is so weird.
Ankita Bose
please check the "Topology Only (Toggle scaling of the tree)" tab is selected (boxed in red color in the attached photo). If it is selected, then deselect it by clicking over it. I hope it will work.Thank you very much.
Deselect "Topology Only" (Toggle scaling of the tree) box as mentioned by Md Firoz Mortuza.
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