The Big Bang
By: Maddie and Abbie
From 5,000,000,000-4,240,000,000 years ago...
- 5,000,000,000 years ago, the sun ignites and the solar system takes its shape.
- 4,640,000,000 years ago, Molten earth forms.
- 4,450,000,000 years ago, the moon forms by collision. Earth's atmosphere initially lacks oxygen (anoxic)
- 4,240,000,000 years ago, The earth forms solid crust. These are the oldest rocks.
From 3,940,000,000-3,540,000,000 years ago...
- 3,940,000,000 years ago, the ocean forms over the crust.
- 3,880,000,000 years ago, In the ocean, organic molecules accumulate as films and membranes.
- 3,740,000,000 years ago, prokaryotes form, single celled bateria. Cells arise as molecular systems become enveloped by membranes. Heredity is mediated through RNA. RNA also acts as catalyst for protien synthesis.
- 3,540,000,000 years ago, photosynthesis generates oxygen while providing energy for further development and experimentation. This oxygen plus any generated by the break down of water vapor or otherwise, gets trapped as iron rust. Cells interact, some swollowing others and incorporating them.
From 2,880,000,000-2,100,000,000 years ago...
- 2,880,000,000 years ago, resperation developes within mitochondria, compartments perhaps derived from chloroplasts, yielding a higher energy cell.
- 2,360,000,000 years ago, rapid rise in atmospheric oxygen favors higher energy cells
- 2,100,000,000 years ago, cells with nuclei, eukaryotes, are the earliest fossil evidence. Heredity material is finally protected within its own chamber, the nucleus. Biochemical evolution has resulted in larger cells with more efficent mithchondria and chlorplasts, and cells have begun to colaborate with one another and to specialize.