Lizards vs
                  Dinosaur vs Brids
Phenetic
versus Cladistic perception & classification of Birds

    Given the phylogeny at top left, a traditional phenetic classification scheme (above, middle) emphasizes the perceived dissimilarity of birds from scaly tetrapods like lizards and crocodiles, whereas a cladistic scheme (above, right) will emphasize the more recent common ancestry of birds with crocodiles.

    Modern phylogenetic classifications emphasize character analyses, which show that birds evolved from dinosaurs. For example, crocodiles, birds, and (presumably) dinosaurs have four-chambered hearts and vocalizations, unlike lizards.That is, perceptions of bird distinctiveness from dinosaurs have changed. However, popular discussions, such "Jurassic Park", present this change in perception as showing that "dinosaurs are more similar to birds." That is, perceptions of dinosaur "primitiveness" have changed. This "neo-phenetic" analysis (left & middle, below) produces the phylogenetic pattern from phenetic criteria. The cladistic classification remains unchanged (below, right).

    A note on terminology: systematists favoring a combination of phenetic and cladistic approaches versus those of use only cladistics, both claim to be doing phylogenetic taxonomy. This term is now associated with cladistic taxonomy, whereas phenetics remains associated with 'traditional' taxonomy.


Text material © 2024 by Steven M. Carr