The common features of cladograms from the choices below are:
Each node indicates where two groups arose from a common ancestor.
All cladograms depict nested hierarchies of evolutionary relationships.
Each node indicates where two groups arose from a common ancestor.
A cladogram is a type of phylogenetic tree that shows the evolutionary relationships between different groups of organisms.
It is a branching diagram, with each node representing a common ancestor of the two groups of organisms that branch off from it.
The tips of the branches represent the taxa (groups of organisms) being studied.
All cladograms depict nested hierarchies of evolutionary relationships.
A nested hierarchy is a hierarchy in which each group is contained within a larger group.
For example, birds and crocodiles are more closely related to each other than either is to lizards and snakes.
This is because birds and crocodiles share a more recent common ancestor than either does with lizards and snakes.
The other choices are not common features of cladograms:
Clades are only found in the two most recent nested branches.
This is not true. Clades can be found at any level of a cladogram, as long as they represent monophyletic groups (groups that include all of the descendants of a common ancestor).
A taxon must be closely related to both groups that appear next to it on the tree.
This is also not true. A taxon can be more closely related to one of the groups that it is directly connected to than to the other.
For example, birds are more closely related to crocodiles than to lizards and snakes.
Additional details:
Cladograms are typically drawn with time running from the bottom to the top.
This means that the taxa at the top of the cladogram are more recently evolved than the taxa at the bottom.
The length of a branch on a cladogram does not necessarily represent the amount of time that has elapsed since the group at the end of the branch diverged from its sister group.
Instead, the length of a branch can represent the amount of evolutionary change that has occurred in that group.