1. Diversity – Prokaryotes, Protists, Plants and Fungi l Early Earth and l The Origin of Life

2. Early history of life l Earth~ 4.5 bya l Life~ 3.5 bya l Prokaryotes~ 3.5 to 2.0 bya stromatolites l Oxygen accumulation~ 2.7 bya photosynthetic cyanobacteria l Eukaryotic life~ 2.1 bya l Muticelluar eukaryotes~ 1.2 bya l Animal diversity~ 543 mya l Land colonization~ 500 mya

3. The Origin of Life l Spontaneous generation vs. biogenesis (Pasteur) l The 4-stage Hypothesis: l 1- Abiotic synthesis of organic monomers l 2- Polymer formation l 3- Origin of Self- replicating molecules l 4- Molecule packaging (“protobionts”)

4. Organic monomers/polymer synthesis l Oparin (Rus.)/Haldane (G.B.) hypothesis (primitive earth): volcanic vapors (reducing atmosphere) with lightning & UV radiation enhances complex molecule formation ( no O 2 ) l Miller/Urey experiment: l water, hydrogen, methane, ammonia l amino acids, nitrogen bases, ATP formed l Fox proteinoid formation (abiotic polypeptides) from organic monomers on sand/clay/rock l Vesicle formation – bilayers on clay?

5. Abiotic genetic replication l First genetic material l Abiotic production of ribonucleotides l Ribozymes (RNA catalysts )

6. The Major Lineages of Life