I am new to this and I have just constructed a phylogenetic tree of 24 bacteria isolated from a kefir generated from the PCR-amplified bacterial 16S rDNA partial sequences (ca. 900 bp) based on the maximum likelihood method using Tamura-Nei model (Tamura and Nei, 1993) with 1,000 Bootstrap replications on MEGA 6.0 software after ClustalW alignment. The result is attached.
Q1: I got the score of '14' and '40' at the nodes, are these numbers too low to be convinced about the data? Do these numbers matter when it comes to publication?
Q2: Please see the picture. When the bacteria species of the same clade have the same branch length, does that mean they all have EXACT the same 16S rRNA sequences? Or they are just very closely related?
Q3: Please refer to the picture. Does it mean the organism with the branch length at the farthest right regarded as the newest species that have been evolved among all bacteria tested?
I'd really appreciate your answer/explanation to these questions to help me understand the phylogenetic tree.
Thank you in advance.