BIOL108 Lecture 30: Nov.23 (Transition to Land)

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL108
• Professor: Lien Luong

Document Summary

Continental drift --> pangaea: coastal regions become land-locked. Plants began to colonize the land --> forests. Arthropods and other invertebrates colonizing land --> lots of food. Terrestrial animals have to have some sort of supporting tissue, which is vascular tissue. Desiccation: air is drier than water, so terrestrial organisms need some form of skin or coat to keep all their bodily fluids form leaking out and to protect the embryo. Respiration: aquatic organisms exchange oxygen and co2 in the water, but in the air the organisms need lungs. Reproduction: in the water, organisms would release their gametes directly into the water, which is a problem once they are on land. Locomotion: organisms can swim in the water, which is modified when they move to the land. Temperature: temperatures fluctuate more in air than in water. Terrestrial animals have to evolve adaptations to deal with these fluctuations. Early land plants: no cuticle, vascular tissue or woody tissue.