1. By Aaron Hebson Can Feng Nya Smith
The Origins Of Life By
Aaron Hebson
Can Feng
Nya Smith

2. Formation of Earth and the Moon
Giant Impact Hypothesis:
4.56 billion years ago a Mars sized planet named Theia collided with young earth
Disintegrated mantles of both planets, and the debris formed into Earth’s moon
Evidence: Lunar rocks rich in sodium, potassium, zinc, and lead which is a result of the vaporization
If vaporization did not occur, lunar rocks would be composed of heavy isotopes
HOW THE MOON FORMED!!

3. Heavy Bombardment
Started around 4.1 billion years ago and ending around 3.9 billion years ago
A hypothesis that states a influx of planetary bombardment of comets and asteroids
It was an essential for developing large plants, and were expected to give the plants in our solar systems most of there mass
A hypothesis predicts that the cause of this bombardment was due to the planetary migration of the large gas planets
This caused the asteroid and comets the orbited around them to continuously collide with terrestrial planets

4. Earth’s Cooling Occurred in the Hadeon eon, around 4 billion years ago
Water vapor was formed by collision of large terrestrial bodies
Comets and asteroids that collided with earth contained large amounts of ice
Condensation of this water vapor formed the oceans we know today

5. Stromatolites Time period: 3.5-2.5 billion years ago
Sheets of microbial collect sedimentary particles and undergo photosynthesis
Pillow-like rock formation formed as a byproduct
Proliferation of cyanobacteria soon followed allowing for excess oxygen in atmosphere

6. Primordial Soup
The organic soup model hypothesizes by Miller/Urey suggested that life began from a combination of chemicals resulting in monomers
These monomers were created through some energy source, such as lightning
This organic soup of monomers can then be used to make more complex molecules

7. Hydrothermal Vents
The Deep Vent Model suggests that life formed in hydrothermal vents
These vents are formed when two geographical plates move apart, releasing lava into the ocean
This lava heats the ocean providing safe havens for life to form
Monomers could be present in these vents to sustain life

8. Meteorites
The Solid Reactive Surface Models suggests that organic materials used to create life came from meteorites and comets
These organic materials would be deposited onto the earth’s surface, and later used to create complex beings

9. Monomers- Nucleotides
Nucleotides are simple organic molecules
Composed of one phosphate, a pentose sugar, and a nitrogenous base
These monomers are used to build nucleic acids
The acids can be used for various functions in life such as storage, transfer of vital information, and even enzymes

10. Monomers- Fatty Acids
Monomers used to construct fat through the combination of the fatty acid and glycerol
A long carbon skeleton ending with carboxyl groups
The carboxyl group may differ from each other in their functional group, designating the name of the acid
Extremely hydrophobic

11. Monomers- Phospholipids
Similar to fats except only two fatty acids are attached to the glycerol
Phosphate and Choline groups are attached to glycerol to form hydrophilic head
Fatty acids are remain hydrophobic
Phospholipid bilayer is formed in aqueous solutions, resulting in a membrane

12. Monomers- Micelle
A structural form of phospholipid bilayer in an aqueous solution
Hydrophilic heads form around the fatty acid chains forming a small sphere

13. Monomers- Vesicle A small bubble that forms inside a cell
Enclosed by a phospholipid bilayer
Can form naturally such as endocytosis or exocytosis
Used to organize cellular function, transport, metabolism, etc.

14. Protocells
Aggregates of abiotically produced molecules surrounded by a membrane or membrane-like structure
Exhibit certain properties of life such as a simple reproduction and metabolism

15. Formation of Nucleotides
Abiotically with the help of clay
Miller/Urey’s experiment also showed that an influx of energy could cause the creation of nucleotides

16. RNA Hypothesis
RNA First Hypothesis states that RNA played a significant role in protein synthesis and catalytic functions
Most likely formed due to it’s diverse descendants, mutations, and reduced uniformed structure

17. Ribozymes RNA functioning as catalysts
Make complementary copies of RNA
Remove segments from themselves
Excising other molecules

18. DNA in Cells
DNA formation: one theory suggests that RNA organisms made DNAs.

19. Evolution of Cells- Endosymbiosis
Primitive prokaryotes engulfing: aerobic prokaryote (mitochondrion) photosynthetic prokaryote (chloroplast)

20. Multi-cellular Organisms
First multicellular organism: 1.2 bya, small algae.

21. Cambrian Explosion Around 500 MYA
Sudden Appearance of phyla animals during the first 20 million years of Cambrian period

22. K-T Event
Around MYA
Cretaceous-Tertiary Extinction Event occurred
Thought to of occurred by a large asteroid or increased volcanic activity

23. Homo erectus Homo sapiens evolved from Homo erectus about 200 TYA
Mass Inhabitation (We’re awesome)