Fig. 5
From: Phylogenetic Analysis: How Old are the Parts of Your Body?
An illustration of how phylogenetic trees can be used to answer evolutionary questions. Student-generated topologies (like the one illustrated in Fig. 4) are used to evaluate the relative order in which diverse aspects of the human form arose in evolutionary history. This can be done by locating the most recent common ancestor (MRCA) of all species that share an anatomical or morphological characteristic (e.g., body hair or a vertebral column) and plotting the trait in question on the branch leading to that MRCA