BIOL 1123 Lecture Notes - Lecture 34: Hydrogen Cyanide, Peptide, Lightning

• School: Acadia University
• Department: Biology
• Course: BIOL 1123
• Professor: Allison Walker

Document Summary

13. 7 billion years ago, the big bang happened and gave rise to the first clouds of hydrogen and helium. Gravitational forces collapsed these into heavier elements like carbon, nitrogen and oxygen. Supernovas, which are exploding stars, formed clouds in which simple molecules like water, carbon dioxide and hydrocarbons were formed. Our own solar system began about 4. 6 billion years ago. Earth is about 4. 55 billion years old, but for the first half billion years after its formation, it was too hot to allow water to accumulate on its surface. 4 billion years ago the temperature dropped enough for the outer layers to solidify and for oceans to form. Biological evolution: genetic changes that occur over one to many generations that lead to dramatic changes in traits and even the formation of new species. The origin of life can be broken down into 4 overlapping stages: Nucleotides and amino acids were produced before cells existed;