BI111 Lecture Notes - Lecture 15: Red Algae, Charophyta, Ordovician
Document Summary
What were the selective pressures that shaped the way they evolved. Drastically influenced terrestrial, aquatic and atmospheric conditions. Land plants make up a large part of our diet. Evolution of land plants falls at a really important time on earth. For long periods of time life was restricted to aquatic environments. 450 million years ago first plants colonize above surface of water. All the other animals evolving due to land plants. Land plants first evolved in the ordovician period. Marine and freshwater organisms had dramatically changed the atmosphere (cyanobacteria use water as a reproducing agent, producing atmospheric o2 as a byproduct), co2 levels were still 10x greater than today. Seaweed living half in water and half out. First species to make it onto land: Most likely a type of green algae. 2 forms of chlorophyll (like land plants today) Most cells are photoautotrophs (use light to feed itself)
