"Branch" of humans? Must be an old chart or one drawn up by a special interest group with a point to make. These days humans are where they belong, on the "branch" with the other apes: gorilla, orangutan, gibbon, chimpanzee (maybe more than one species of chimpanzee). Hard to picture this chart. Was it designed for youngsters? It plays fast and loose with Linnaean taxonomy. Amphibians and fish are classes within the phylum of vertebrates. Lizards are an order within the class of reptiles within the phylum of vertebrates. Tadpoles are simply the "larval" stage (if I may borrow the word from entomologists, I don't know what herpetologists call them) of frogs, an order within the class of amphibians. No consistency here. It fails to teach anything, at least not anything accurate, and it seems to actually be misleading. Primates are an order within the class of mammals within the phylum of vertebrates. Modern humans are the only living species (Homo sapiens) within the genus (Homo) of all present and past humans. As far as I can recall, each of the other apes is also a single-species genus. I presume these genera form a family of apes within the class of primates. But vertebrates are famous for having suborders and subclasses and subfamilies so I could be wrong about that last part.