EEB 390 Lecture Notes - Lecture 13: Ciliate, Deoxyribozyme, Chloroplast

• School: U of M
• Department: Ecology and Evolutionary Biology
• Course: EEB 390
• Professor: Jeff Smith

Document Summary

Lecture 13: earliest life around 4 billion years ago. Fossils: bit of rock that is dated below the rock something above and something below microfossils: microscopic fossils (typically smaller than 1-4 millimeters: 3. 2 billion years old, javaux et al. , 2010. Biomarker: molecular evidence of life in the fossil record. Can be dna, lipids, isotopic ratios: things that would be left by some biotic organism, ex > speck of carbon in a zircon mineral which can be preserved for billions of years. Stromatolite: layered calcareous structures formed by bio lms (microorganisms adhered together) binding sedimentary grains: when they get married they are fossilized. We know there was life by 3. 7: several that were dated parts of stromatolites that were fossilized. First evidence for life on earth pushed back 220 million years to 3. 7 billion. This is an active area of research continues to change. Last universal common ancestor (luca): the population of organisms at the base of the tree of life.