Cladograms

Cladograms are a way for us to observe and analyze characteristics and evolutionary change between two phylums. Starting out with a character matrix allows us to determine synapomorphies and apomorphies between theses two group, allowing us to construct the cladogram (Reece). My cladogram consisted of various phylums from the Animal Kingdom. The outgroup for my cladogram was the Choanoflagellates due to the fact that “they are the closest, living, unicellular relatives of animals” (Leadbeater). The phylum Prorifera has the ability to be asymmetrical and to reproduce by budding, but lacks true tissue. True tissue was the next evolutionary adaptation that is present in phylum Cnidaria. Multicellularity and the presence of true tissue are indicators
The protostome grouping consists of Nematoda, Onychophora, Arthropoda, Platyhelminthes, Brachiopoda, Mollusca, and Annelida. Nematoda, Onychophora, and Arthropoda are classified and the Ecdysozoa group. Platyhelminthes, Brachiopoda, Mollusca, and Annelida are classified as the Lophotrochozoans. Possessing the traits of a psuedocoelomate and thrashing, was Nematoda. Although classified low on the cladogram, Nematoda are highly diverse and complex metazoans (Paul De Ley). Onychophora, and Arthropoda share the trait of segmentation, but Arthropoda additionally possess an exoskeleton made of chitin, jointed appendages, and a segmented thorax, abdomen, and head. Onychophora (velvet worms) have a character
Five-part penta-radial symmetry, a spiny protective skin, and a water vascular system are traits specific to the phylum Echinodermata. The more detailed cladogram for Echinodermata shows apomorphic traits for each class. The notochord, pharyngeal slits, endostyle/thyroid, dorsal hollow nerve chord, and post-anal tails shows the evolutionary traits present in the phylum Chordata. All chordates at some point in development will exhibit these traits. Chordates can be distinguished as being vertebrates or invertebrates (Harris-Haller). Two separate cladograms were constructed to show this difference. The vertebrata subphylum of the Phylum Chordata all possess the 5 chordate characteristics, backbone, bony/ cartilage skull protecting the brain, and an endo skeleton made of bone. The Cyclostomes (Myxini and Petromyzontida) are linked together due to the fact that they both lack a jaw. Synapomorphies include Myxini not having a backbone and Petromyzontida having a rasping tongue. The development of two sets of paired appendages and a jaw resulted in the grouping called Gnathostomada. This grouping includes Chondricthyes, Actinopterygii, Actinistia, Dipnoi, Amphibia, Reptilia, and Mammalia. Within the