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

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!! http://dsc.discovery.com/tv-shows/other-shows/videos/other-shows-how-the-universe-works-videos.htm

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

K-T Event Around 230-65 MYA Cretaceous-Tertiary Extinction Event occurred Thought to of occurred by a large asteroid or increased volcanic activity

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