Here in the explanation of cladistics is part of the problem with these artificial groupings, the cladogram is used to prove the assumption that its construction is based upon:
“What is Cladistics
Lynne M. Clos
.........Derived characters are advanced traits which only appear in some members of the group. Cladistics is based on the assumption that the appearance of derived characters gives clues to evolutionary relationships. In our example, a derived character for some mammals might be loss of the tail, which occurs in the great apes and man. It is assumed that loss of the tail occurred only once, in the common ancestor of apes and man, and that none of us has one because we inherited that trait from our common ancestor. Thus if mammals are separated into groups which do and which don't have a tail, shown by a fork on the evolutionary diagram (cladogram), this represents the point at which a new species evolved which didn't have a tail. Man and the great apes are assumed to have descended from this species (which may or may not remain undiscovered at the present time).”
Say what? The formation of the group is based upon shared evolutionary traits and descent is shown by the grouping?
Speciation events? What speciation events? Solid black lines showing a connection between two other black lines?What is at these intersections?
Your source is woefully inadequate if you want to understand how cladistics is done. It is done with DNA comparisons. A “clade” is a branch that all share the same evolutionary feature (even if they lose it), but cladograms are constructed by DNA analysis.
But of course you wouldn't be expected to know that if you rely on Creationist sources, they misrepresent the science they attempt to debunk out of necessity.