NATS 1740 Lecture Notes - Lecture 17: Cambrian Explosion, Tardigrade, Cyanobacteria

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Michael De Robertis, Alireza Rafiee

Document Summary

Microscopic, enclosed membranes or pre-cells have been created in the lab (+) chemicals to life (+) life migrated to earth. Venus, earth and mars have exchanged tons of rock (blasted into orbit by impacts) Some microbes can survive years in space. Even animals, the tardigrade which can survive some time in space (+) brief history. Early ocean forms zero oxygen: 4. 4 billion years. Cyanobacteria start releasing oxygen: 3. 5 billion years. Oxygen begins building up in atmosphere: 2 billion years. Cambrian explosion short period : 540-500 million years. Dinosaurs and small mammals (dinosaurs ruled): 225-65 million years. Earliest hominids: few million years (+) origin of oxygen. Liquid water (or possibly some other liquid) Life in the outer solar system: could there be life on mars. There is evidence of water in the past. Subsurface ice => probably subsurface water near sources of volcanic heat. Ganymede, callisto also have evidence of subsurface oceans (+) titan.