Branching diagram showing evolved relationships among members of a lineage.

• A. Reproductive variance
• B. Speciation
• C. Cladogram
• D. Biological species concept

Answer: (C)

This question is about recognizing a diagram that maps evolutionary relationships in a branching, tree-like form. A cladogram is a branching diagram used in cladistics to illustrate hypotheses about descent from common ancestors, with the pattern of branches showing how lineages diverge and which groups are more closely related based on shared derived characters. It emphasizes relationships and ancestry rather than timing or the amount of change.

Reproductive variance deals with differences in reproductive success among individuals, which isn’t about depicting relationships. Speciation is the process by which new species arise, not the diagram itself. The biological species concept defines what counts as a species in terms of reproductive isolation, which is about defining categories rather than illustrating evolutionary branching.