BIO 1130 Lecture Notes - Lecture 3: Lamprey, Occipital Condyle, Necturus

• School: University of Ottawa
• Department: Biology
• Course: BIO 1130
• Professor: Jon Houseman

Document Summary

A cladogram displaying all the species linked to one common ancestor. Having a stomach present as an organ is one of the most primitive traits relative to the other traits examined. The presence of a stomach in the species separates the lamprey (sister group) from the rest of the species. A trait for species that have teeth on their jaws, easily distinguished from the lamprey (sister. Group), adding an extra trait to the cladogram. The advantage of having teeth on jaws is allowing the stomach to digest the ingested food easier by breaking it down into smaller portioned pieces, preparing it for digestion. Other species such as humans, mudpuppies and rats also excrete nitrogenous waste in the form of urea. Cladogram (5): lungs & derivatives trait 9(1) The rest of the species have some form of a certain respiratory system, being either lungs or some derived structure such as a swim bladder.