1. Chapter 14 – where did it all begin?
Origin of Life
Chapter 14 – where did it all begin?

5. Disproving Spontaneous Generation
Life from nothing
Bio/Genesis
Life coming from life

6. Key players
Redi
Spallanzani
Pasteur

7. Redi’s Experiment
Mid-1600’s – People though that flies spontaneously arose from meat
Francesco Redi (1668) hypothesized that meat kept away from adult flies would remain free from maggots
Experiment gave good evidence for flies coming only from eggs laid from other flies

8. Spallanzani’s Experiment
Lazzaro Spallanzani (1700’s) – designed an experiment to test for microorganisms
Hypothesized that microorganisms living in the air and would contaminate the broth in the unsealed flask
Opponents claimed that he killed the “vital force” by boiling the broth too long
Failed to disprove spontaneous generation

9. Pasteur’s Experiment
Louis Pasteur (mid-1800’s) – Also believed that microorganisms lived in the air
Proved, with his year-long experiment, that microorganisms (life) lead to life, not a “vital force” in the air

10. Needs for life
CHON
Heat
Electricity
WATER!!

11. The First Organic Compounds
Miller and Urey (1953) experimentally recreated Earth’s early conditions and found amino acids

12. Life from Organic Compounds
Microspheres
Proteins organized as a membrane
Coacervates
- globs of organic compounds
- pre-cursers to first cells

13. 1st Cells Prokaryotes Anaerobic Heterotrophic/Chemosynthetic ozone
Autotrophic
Aerobic
ozone

14. The First Eukaryotes
Endosymbiosis – engulfing simple prokaryotes leads to more complex cells
“Specialization” and division of labor