EAS 1540 Lecture Notes - Lecture 4: Solar Wind, Archaea, Snowball Earth
15 Dec 2016
School
Department
Course
Professor
Document Summary
Lec 4 - wed 8/29 - evolution of life on earth. Evolution of life on earth (dr. robert ross, paleontological research institute / museum of the. Density of earth changes - nickel and iron move towards core. Have rocks that are 4 billion years ago - have minerals in them. Everything is related - bacteria started it all. Bacteria cells are so small compared to human cells. Lots of iron in rocks --> there was a lot of oxygen in the atmosphere. Bacteria have an important influence in atmosphere, ocean chemistry, etc. Atmospheric composition: co2, o2, n2, methane, ammonia, water. Most eukaryotes are one celled organisms - most are things other than fungi, animals, plants. Rocky earth -> prokaryotes -> eukaryotes -> snowball earth. And then we start seeing things that kinda look like animals. Found in australia - ediacaran fossils ~600 mill years ago. Most major animal groups known today appeared within a span of 30 years.
