Hello,

In the same genus we can see many different species, having not all a support value "0" (zero). In reality, the genus not exist (this is taxonomical reality); so, it need to study the species (the organisms ).

Best regards

There is 96% support for the (Q,R,S,T) clade being separate from the rest of the sequences. The zeros are back near the root of the tree.

In general, the "molecular clock" ticks roughly equally for all related organisms. Viruses evolve faster than mammals, for example, but all mammals evolve at somewhat similar rates. Your tree shows long and short branches, which is indicative of either too little data, or recombination, or both, and/or other factors. And these factors will all tend to result in decreased support. A tree made form too little data is not "useless" because we can clearly see that (Q,R,S,T) are almost identical to each other and that (G,H,I) are diverse but strongly related to each other. But we cannot be confident that M is some sort of fossil ancestor of the (Q,R,S,T) sequences, it may instead be a recombinant between two lineages.

https://www.researchgate.net/post/What_does_number_indicates_at_nodes_in_phylogenetic_analysis