Final answer:
The purpose of a phylogenetic tree is to illustrate the evolutionary relationships among species. It is a diagrammatic representation using nodes to indicate common ancestors and branches to depict the divergence into new species, alongside the timeline of evolutionary events.
Step-by-step explanation:
The purpose of a phylogenetic tree is c) To represent the evolutionary relationships among species. This tool is used by scientists to illustrate the pathways and connections in the evolution of various life forms. A phylogenetic tree is a diagram that reflects these relationships through nodes and branches, where nodes represent common ancestors and branches indicate divergence into new species. The diagram may also show how long ago these divergences occurred, highlighting the passage of time in evolution.
Phylogenetic trees and cladograms serve as models that encapsulate the evolutionary history of organisms, which can then be tested with scientific evidence and questions. It's important to note that these trees and cladograms are considered hypotheses, as they are based on current scientific understanding and evidence, and cannot be confirmed by going back in time.