BIO 1130 Lecture Notes - Lecture 10: Cecum, Eyelid, Nictitating Membrane

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

Document Summary

Lecture 10: chapter 3, charles darwin and evolution continued. Evolution of the horse: classic interpretation. Linear path of growth, new structures, etc. This type of image showing evolution is wrong; evolution is not simply linear like this, and does not occur by progressive elimination: more realistic interpretation (phylogenetic tree) Trees provide a better interpretation of evolution. 5 different species of horses alive at the same time (seen in fossils) Pakicetus: as tree branches, mammals that are more and more adapted to live in water. Whales: no hind legs; do have a pelvis: based on this we would say that the closest relative to whales in current fauna is the hippopotamus. Vestigial structure: anatomic structure that has lost almost all of its initial function. Nictitating membrane or third eyelid in humans: translucent membrane and goes from corner of the eye and can cover the entire eye. Fish, chicken, birds still have this structure (to protect eyes from environment)