Answer:
Collagen genes.
Step-by-step explanation:
Phylogenetics helps to study the evolutionary relationship among the different group of organisms. The different characteristics like DNA sequences, mitochondria sequences can be used for the construction of phylogeny tree.
Collagen genes can be used to study the evolutionary relationship as mammals contains nearly 30% of total protein. The collagen gene shows the most of the conserved sequences among the different group of organisms and shows the most recent evolved characters in vertebrates.
Thus, the correct answer is collagen genes.