Early Earth & the Origin of Life

Chapter 26

Clock analogy for some key events in evolutionary history

Early Earth

Louis Pasteur

Pasteur and biogenesis of microorganisms (Layer 1)

Pasteur and biogenesis of microorganisms (Layer 2)

Pasteur and biogenesis of microorganisms (Layer 3)

The Miller-Urey experiment

RNA may have been the first genetic material

• RNA acts as a template to make polypeptides

• Polypeptides act as primitive enzymes to replicate RNA

• Exclusive relationship evolves with membrane

Hypothesis for beginning of molecular cooperation

Protobionts: Pre-cells

The History of Life

5-Kingdom System

Things are Changing…