1. Where does Life come from?
Theories & Scientists

2. Big Bang Theory https://www.youtube.com/watch?v=u0ZP152mALk

3. Life Origins Earth is estimated to be 4.6 billion years old
Rocks in Australia have fossils 3.5 billion years old

4. Spontaneous generation
the idea that living things come from nonliving things
Example: earthworms from rain, mice from hay.

5. Biogenesis
living things come only from other living things

6. Scientists

7. Francesco Redi

8. Redi’s Experiment

9. Experiment: tested jars with meat; covered ½ and left ½ uncovered (open to the air);
Outcome/Conclusion: maggots only appeared on the uncovered meat, maggots must come from fly eggs and not the meat

10. Lazzaro Spallanzani

11. Experiment

12. Experiment: boiled broth in sealed flasks; then he opened some
Outcome/Conclusion: only opened ones became contaminated, organisms from the air were the cause of contamination

13. Louis Pasteur

15. Experiment: boiled broth in s-shaped flasks, then tilted some over
Outcome/Conclusion: broth in tilted flasks mixed with dust and became contaminated, disproved the theory of spontaneous generation

16. Oparin’s hypothesis- gases like ammonia, hydrogen, methane, & water vapor made up Earth’s early atmosphere and could combine to form living compounds

17. Miller & Urey- tested Oparin’s hypothesis and showed that amino acids could be produced