Transcript How Life Began - Londonderry NH School District

How Life Began
http://cmex.ihmc.us/VikingCD/Puzzle/Evolife.h
tm
1. Physical and Chemical
Characteristics
– A. Early atmosphere
was thicker with
carbon dioxide and
red in color.
– B. The ocean was
olive in color
– C. Great
Bombardment
Asteroid/meteorite
bombardment
created harsh
conditions
http://www.physicsoftheuniverse.com/topics_life_early.html
2. Early Environment SurvivorMexican Cave Analogy
Chemosynthetic bacteria:
use Hydrogen Sulfide
for energy source;
survives in snotites or in
phlemballs.
http://www.caveslime.org/Photos/Snottites
3. Carbon
• A. Basis of living things.
• B. Bonds to form diverse
compounds.
• C. Miller’s experimentamino acids that contain
carbon formed in harsh
conditions similar to early
Earth.
• D. Old rocks in Greenland
contain carbon.
http://www.geus.dk/viden_om/voii/ilulissatuk/voii05-uk.html
4. Great Bombardment
• A. Asteroid and comet bombardment
• B. Tons of dust from the Universe bombards
Earth.
• C. Dust contains carbon, elements, compounds
and minerals.
• D. The building blocks of life, amino acids, form
then peptides/protein.
• E. Collision Simulation Experiment- amino acids
survived force similar to comet impact and fused
to form larger molecules or peptides.
5. Environments where life could be
protected from great bombardment
• A. Underground- microbes live in dark places
and use chemicals like methane, propane, and
ethane, for food and energy: chemosynthesis.
• B. Deep ocean- microbes live on chemicals
like Hydrogen Sulfide for food and energy:
chemosynthesis.
Amino acids, peptides, and proteins
www.chemicalconnection.org.uk
commons.wikimedia.org
www.sigmaaldrich.com
6. Environment less hostile due to
decreased bombardment
• A. Bacteria moved to shallow ocean and used Sun’s
light energy, carbon dioxide and water to make food
and release oxygen: photosynthetic bacteria.
• B. Bacteria evidence found in stromatolites, the oldest
fossils.
• C. Cyanobacteria: first to use photosynthesis, release
oxygen as a waste product.
• D. Oxygen absorbed into oceans and combined with
iron to form oxides.
• E. Cyanobacteria starts the increase of oxygen from 1%
to 21% (today), allows diversity of life, forms O3
(ozone) which provides a protective layer vs. UV.
Cyanobacteria
http://www.uni-frankfurt.de/%7eschauder/cyanos/cyanos.html
http://commons.wikimedia.org/wiki/File:Efflorescence_verte_4_Cyanobacteria
Stromatolites
www.aslo.org
http://www.sharkbay.wa.gov.au/tourism/what_to_see_and_do/
http://www.geology.sdsu.edu/seminars/fall08/10_29_08.html
Iron ore
http://www.constructionweekonline.com/article-9234-qatar-steel-secures-long-term-iron-ore-supply
/
Order of Events of How Life Began
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Solar Nebula
Accretion
Bombardment
Radioactive decay
Iron Catastrophe
Magnetic Field
Volcanoes
Plantesimal hits Earth- tilt
Moon moves away
Water on surface, crust forms
Great Bombardment
Chemosynthetic bacteria
Great bombardment ends
Photosynthetic bacteria form; cyanobacteria
Order of appearance of living things on
Earth
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
4 elements- C, O, N, H
Amino acids
Peptides
Proteins
Microbes-chemosynthetic
Cyanobacteria- photosynthetic
Multicellular organisms
Plants
Fish
Insects
Reptiles
Dinosaurs
Primates
First humans