the origins of life
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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 - PowerPoint PPT PresentationTRANSCRIPT
ByAaron Hebson
Can FengNya Smith
Formation of Earth and the MoonGiant Impact Hypothesis:4.56 billion years ago a Mars sized planet named
Theia collided with young earthDisintegrated mantles of both planets, and the debris
formed into Earth’s moonEvidence: Lunar rocks rich in sodium, potassium, zinc,
and lead which is a result of the vaporizationIf vaporization did not occur, lunar rocks would be
composed of heavy isotopesHOW THE MOON FORMED!!http://dsc.discovery.com/tv-shows/other-shows/videos/other-show
s-how-the-universe-works-videos.htm
Heavy BombardmentStarted around 4.1 billion years ago and ending
around 3.9 billion years agoA hypothesis that states a influx of planetary
bombardment of comets and asteroidsIt 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 CoolingOccurred in the Hadeon eon,
around 4 billion years agoWater 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
StromatolitesTime period: 3.5-2.5
billion years agoSheets 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 SoupThe 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 VentsThe 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
MeteoritesThe 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- NucleotidesNucleotides are simple organic
moleculesComposed 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 AcidsMonomers 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- PhospholipidsSimilar 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- MicelleA structural form of phospholipid bilayer in
an aqueous solutionHydrophilic heads form around the fatty acid
chains forming a small sphere
Monomers- VesicleA small bubble that
forms inside a cellEnclosed by a
phospholipid bilayerCan form naturally
such as endocytosis or exocytosis
Used to organize cellular function, transport, metabolism, etc.
ProtocellsAggregates 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 NucleotidesAbiotically with
the help of clayMiller/Urey’s
experiment also showed that an influx of energy could cause the creation of nucleotides
RNA HypothesisRNA 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
RibozymesRNA functioning
as catalystsMake
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 ExplosionAround 500 MYA Sudden Appearance
of phyla animals during the first 20 million years of Cambrian period
K-T EventAround 230-65
MYA Cretaceous-
Tertiary Extinction Event occurred
Thought to of occurred by a large asteroid or increased volcanic activity
Homo erectusHomo sapiens evolved from Homo erectus
about 200 TYAMass Inhabitation (We’re awesome)