how did life get here n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
HOW DID LIFE GET HERE? PowerPoint Presentation
Download Presentation
HOW DID LIFE GET HERE?

Loading in 2 Seconds...

play fullscreen
1 / 5

HOW DID LIFE GET HERE? - PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on

Direct evidence :. Fossilised chains of bacteria-like cells found in Marble Bar W.A. Occur in rocks dated at 3500 M yr ago. HOW DID LIFE GET HERE?. Still being debated as possible these structures were produced by geological action NOT biological. First signs of life?.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'HOW DID LIFE GET HERE?' - lorne


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
how did life get here

Direct evidence:

Fossilised chains of bacteria-like cells found in Marble Bar W.A.

Occur in rocks dated at 3500 Myr ago

HOW DID LIFE GET HERE?

Still being debated as possible these structures were produced by geological action NOT biological

First signs of life?

slide2

Earth 3,500 Million Years Ago

Anoxic atmosphere:

Nitrogen, carbon dioxide, methane, ammonia, sulphur dioxide and hydrogen sulphide

Extreme UV radiation:

No ozone

Extreme weather conditions:

Water cycle

Extreme geological activity:

Volcanoes, earthquakes

slide3

What is needed for life?

Liquid water:

Provides medium for reactions to occur and

an essential solvent.

Usable energy source:

Needed for all life’s functions.

The chemicals that make up all life

Organic molecules:

Two Hypotheses

1. Organic molecules produced on early Earth

Aleksandr Oparin and J.B.S. Haldane suggested that the organic molecules needed for life were produced under the conditions on early Earth. (1920’s)

In the 1950’s Stanley Miller and Harold Urey set up a MODEL of early Earth to test Oparin and Haldane’s hypothesis.

slide4

Sparks, electrical discharge

Lightning in storms

Gases, CH4, NH3, H2O, H2

Gases found in Early Earth atmosphere

Condenser

Water vapour due to water cycle

Vacuum

Boiling water

Water in newly formed oceans

1 week later:

Organic molecules found in the water

Showed that organic matter can be produced from inorganic material.

slide5

2. Organic molecules arrived from space.

1969 – meteorite found in Victoria contained amino acids

Confirms organic molecules can be formed outside Earth

Early Earth was constantly bombarded with meteorites due to developing Solar System

Supports the idea that organic molecules arrived from space.

2001 – NASA replicated in the laboratory conditions that exist in interstellar clouds in space

Water mixed with inorganic chemicals, NH3, CO, CO2, CH3OH

Freeze to absolute zero in a vacuum

Expose to shortwave UV radiation

Results:

Complex organic molecules