1. ORIGIN OF LIFE Which organism do you think evolved first?B
Which organism do you think evolved first?
Support your answer

2. What do you think early earth was like?
How old is the Earth estimated to be?
4.6 billion years old

3. Early Earth was a hostile & violent place
Very hot
CO2…H2…N2…NH4…
CH2…H2O vapor
Storms..lightning…
volcanic eruption…meteor strikes
NO O2
NO LIFE

4. CAN SCIENCE EXPLAIN THE ORIGIN OF LIFE?

5. OPARIN’S PRIMORDIAL SOUP
1930s…Alexander Oparin proposed that the life began about 3.9 billion years ago
The earth cooled…causing RAIN
Oceans formed
Energy from sun…lightning…Earths heat triggered chemical reactions among the element of early earth & the atmospheric gases
This produced simple organic compounds

6. 1950s…Miller & Urey test the hypothesis
Boiled water to create water vapor
Added gases through valve
Used electricity to simulate lightning
Condenser cooled everything
What did they find?

7. Simple organic compounds!
Sugars, amino acids

8. Label diagram in your notes

9. What were first organisms like?
ANAEROBIC… no oxygen
HETEROTROPHIC: lots to eat
PROKARYOTIC… simple organisms; few organelles; no need for nucleus yet

10. As food runs out… Organisms need to make food… First AUTOTROPHS
Development of chloroplast … mitochondria… NUCLEUS… EUKARYOTES

11. FIRST MASS EXTINCTION
Evolution of autotrophs…leads to production of OXYGEN in the environment
Most anaerobes become extinct

12. GEOLOGIC TIME
ERA
PERIOD
EPOCH

13. Can you name the 4 eras. What distinguishes one era from the next
Can you name the 4 eras? What distinguishes one era from the next? Why do we know so little about the Precambrian? In what era(s) did mammals exist?

14. Where do bacteria come from?

15. Spontaneous Generation

16. Redi’s Experiment Describe the experiment
Which jars would you expect to contain maggots/flies
BUT THE SEALED JAR KEPT OUT AIR!
Redi used cheese cloth
Redi’s Experiment

19. Pasteur’s Experiment

20. IN SUMMARY…

21. BIOGENESIS

22. Fossil evidence shows that Archaeopteryx, a small dinosaur, had feathers. What does this tell scientists? A. that Archaeopteryx could fly B. that feathers evolved after fur C. that birds may have evolved from dinosaurs D. nothing