chemical evolution and the origin of life

1
Chemical Evolution

• Prepare by Rozh Bahman Tahir
• Lesson Teacher Mrs. Rezan Latif
• School Kurdistan Educational compound (KEC)

2
Chemical Evolution Theory of Lifes Origins

• Chemical Evolution definition The formation
  of complex organic molecules from simpler
  inorganic molecules through chemical reactions in
  the oceans during the early history of the Earth
  or the first step in the development of life on
  this planet.
• This idea was first proposed in the 1920s and is
  known as Oparin-Haldane hypothesis and was
  published in 1952 by the Urey-Miller experiment.

3
The Oparin-Haldane Hypothesis

• In the early decades of the 20th century,
  Aleksandr Oparin in (1924) and John Haldane
  independently suggested that if the primitive
  atmosphere was reducing and if there was an
  appropriate supply of energy, such as lightning
  or ultraviolet light, then a wide range of
  organic compounds might be synthesised. 

4
The Oparin-Haldane Hypothesis

• According to their theory, life evolved in the
  oceans during a period when the atmosphere was
  reducing - containing H2, H2O, NH3, CH4, and
  CO2, but no free O2.
• Organic compounds were synthesized
  nonbiologically by ultraviolet light energy.
• These compounds accumulated in a "soup" which
  they named as primordial soup that may have
  concentrated at various locations ( shorelines,
  oceanic vents etc).

5
The idea of MillerUrey experiment

• The MillerUrey experiment was a
  chemical experiment that simulated the conditions
  thought at the time to be present on the early
  Earth, and tested the chemical origin of
  life under those conditions. The experiment
  confirmed Alexander Oparin and John Haldane's
  hypothesis. it was conducted in 1952 by Stanley
  Miller, with assistance from professor Harold
  Urey, at the University of Chicago and later
  the University of California, San Diego and
  published the following year.

6
The early Atmosphere of our planet Earth

• The early atmosphere was composed of some
  kind of volcanic conditions like Ammonia
  gas(NH3), Methane(CH4), hydrogeb (H2) which is
  highly exclusive and we said it was like an early
  volcano so we add hydrogen sulfide(H2S), and
  Nitrogen(N2) as well as Carbon dioxide(CO2) and
  of course some water vapor (H2O).

7
How did Miller-Urey experiment work?

• The experiment used water (H2O), methane
  (CH4), ammonia (NH3), and hydrogen (H2). The
  chemicals were all sealed inside a sterile
  5-liter glass flask connected to a 500 ml
  half-full of liquid water. The liquid water in
  the smaller flask was heated to
  induce evaporation, and the water vapour was
  allowed to enter the larger flask. Continuous
  electrical sparks were fired between the
  electrodes to simulate lightning in the water
  vapour and gaseous mixture, and then the
  simulated atmosphere was cooled again so that the
  water condensed and trickled into a U-shaped trap
  at the bottom of the apparatus

8
How did Miller-Urey experiment work?
9
How did Miller-Urey experiment work?
10

• Thanks for watching

• Sources
• www.chem.ox.ac.uk
• en.wikipedia.org
• www.uic.edu