Mr. Hoeldtke

Where did life come from?

3.6 billion years ago

Nitrogen

Water Vapor

CO2

Methane

Hypothesis:

Did not need oxygen to survive

Unicellular organisms

Able to survive extreme environments

Lived in Ocean

Example: Archaebacteria

Plants and microorganisms release oxygen during photosynthesis

Microorganisms create oxygen through similar processes

Allows for the organisms around us to survive

Dinosaurs were huge?

Urey and Miller (1953)

Mixture of Nitrogen, CO2, methane and water vapor

Electricity (lightning)

Ensured that no oxygen or unicellular organisms in mixture

Why?

Found some of the building blocks of life (pre-proteins)

Other scientists had similar experiments that had precursors to nucleic acids and carbs.

Hypothesis: That cells formed gradually over millions of years in earth’s early oceans

Fossils

Preserved remains of organisms under certain conditions

Bacteria-like organisms found that were dated 3.5-3.6 billion years old

Would use chemical energy and have oxygen as a waste product

Eventually, chemical resources depleted

Cells that survived would need another energy source

Photosynthesis

Thanks plants