Final answer:
The most closely related taxa should have the most characteristics in common, following the principle of maximum parsimony, which aligns with taxonomic classification and genetic similarities demonstrated in DNA sequences.
Step-by-step explanation:
The most closely related taxa should have the most characteristics in common. This concept is rooted in the principle of maximum parsimony, which suggests that organisms sharing a greater number of traits are more likely to share a common ancestor. When examining taxonomic classification, it reveals that within a particular family, there can be many genera; and within each genus, there are various species. These levels of classification get more specific and the organisms more closely related as you move from domain to species.
DNA sequence similarities among closely related organisms further validate this relationship, showing evidence of shared ancestry. Consequently, two closely related species would share more genetic similarities with each other than with species from different genera or families. Moreover, a phylogenetic tree visually represents these relationships, with more recently evolved organisms placed closer to the tips of the branches, indicating that they share more recent common ancestors.