What type of diagram is used to illustrate evolutionary relationships?

A phylogenetic tree is the correct choice for illustrating evolutionary relationships because it visually represents the evolutionary pathways and connections between different species or groups. These diagrams are structured to show how various organisms have diverged from common ancestors over time, typically incorporating the concept of common descent. The branches indicate points where lineages have split, promoting an understanding of evolutionary history and the degree of relatedness among species.

In constructing a phylogenetic tree, scientists often use molecular data, fossil records, and morphological characteristics to determine these relationships, allowing for a depiction of how species evolved and adapted over millions of years. This essential tool in biology helps researchers comprehend biodiversity and the evolutionary processes that have shaped life on Earth. Other options, while related to evolutionary concepts, do not specifically serve the primary purpose of depicting evolutionary relationships in the same systematic way.