DO NOW Take your time travel machine and go back in time with your partner sitting next to you about 4 million years. What would you find on Earth? Describe what it looks like and how you feel being there.

Early Earth Formation began approximately 4.6 billion years ago. Oparin-Haldane Hypothesis: Composition of the early Earth’s atmosphere: Water vapor Carbon Monoxide Hydrogen Sulfide Methane Hydrogen

Miller-Urey Experiment First scientists to provide evidence for the possible creation of life. Simulated the conditions of the early Earth, which created the building blocks of life!

Spontaneous generation (Abiogenesis)

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For much of history, people believed that animals could come from non-living sources. This was known as spontaneous generation

Francesco Redi Observation: Flies land on meat and later maggots appear

Meat exposed to the outside environment Meat sealed in air tight container Meat covered with cheese cloth

What did Francesco Redi prove? Living things did NOT come from non-living things (Maggots did not come from rotting meat, but from flies)

Louis Pasteur Observed liquids such as milk, wine, and vinegar He hypothesized that these liquids were becoming sour because they were being contaminated by microorganisms in the air

After Several weeks

What did Louis Pasteur prove? Germs come from other germs (Germs in the air contaminated the nutrient broth)

The First Living Cells The first cells: Prokaryotic- one cell Anaerobic- “without air” Heterotrophic- rely on a carbon source The competition for food created autotrophs The CO2 created by heterotrophs and O2 created by autotrophs changed the atmosphere on Earth

No nucleus Most primitive, early forms of life No membrane bound organelles True nucleus More complex organisms Reproduce sexually with the use of meiosis. Eukaryotic Cells Prokaryotic Cells

Evidence and Theory of Evolution

The Fossil Record

Fossils  Direct or indirect remains of organisms preserved in material such as:  Sedimentary rocks  Amber  Ice  Tar  Single celled organisms date back to 3 billion years ago.  About a billion years ago multi- celled organisms began to evolve. Relative Dating of Undisturbed Sedimentary Rock and its Fossils Upper strata generally contain fossils of younger, more complex organisms, whereas, the lower strata contain fossils of simpler life forms. This means there is a tendency toward increasing complexity in life forms over time.

The Law of Superposition  Nicolaus Steno (1669)  Younger strata will be deposited on-top of older strata.  The higher up you go in an undisturbed rock layer, the younger the rock layers become and therefore it is believed the fossils within these layers, as compared to lower rock layers.  Common ancestors can be determined.