NATS 1740 Lecture 16: 8th February 2019

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

Document Summary

Hadean period: the whole planet is extremely hot, molten. Life perhaps arose more than 3. 85 billion years ago, after the end of heavy bombardment. Fossils die long time again, we can"t bring back the fossil to alive again. We find fossils most the time in sedimentary layer. Ex: rock layers of grand canyon proves more than 500 million years of earth"s history. The oldest fossils look like layers, called the bacteria-like organisms were present over 3. 5 billion years ago. Evidence from carbon isotope pushes the origin of life more than 3. 85 billion years ago. We know by studying the dna from the ancestor. + the fossil record shows that evolution did happen through time. + darwin"s theory shows how evolution occurs through natural selection (however, we don"t know if this theory supported by dna) + the theory is supported by the discovery of dna (discovered far later): evolution proceeds through mutations. Tree of life: the genetic map relationships.