OPARIN –
HALDANE
THEORY

INTRODUCTION
The only thing that goes up and
never down is time or age. With time
and age, many things change including
new constructions, modification as
needed to be fittest, destruction of unfit
ones and even extinction. All these
things are under evolution.
Oparin – Haldane Theory was the
first widely accepted scientific theory of
organic evolution.

Given by :- A. I. Oparin (1924) & J. B. S. Haldane
(1929).
Supported by :- Miller & Urey – 1953.
Phases of organic evolution as per this theory :-
The cosmos
The primitive earth
The atomic phase
Cooling of earth
Origin of molecules and simple compounds
Origin of organic compounds
Coacervates
First living cell or protovirus
Monerans
Protistans and autotrophism
Fungi, plantae and animalia

THE COSMOS OR UNIVERSE
 Universe is made of countless number of galaxies.
 Galaxies are huge groups of billions of star systems.
 Milky way is our galaxy with about 100 billion stars
besides our sun.
 Our sun is a star of about 5 billion years old, it is in
rapid burning & motion.
 Our solar system includes 8 planets, some dwarf
planets, satellites, asteroids, and other heavenly
bodies.
 The 8 planets are Mercury, Venus, Earth, Mars,
Jupiter, Saturn, Uranus, Neptune. (My Very Easy
Method Just Studied Under News)
 We will study organic evolution on earth.

THE ORIGIN OF EARTH
 Big bang theory :- The universe originated from a
gigantic explosion of a fireball, scattering
outwards.
 Gaseous clouds, mainly Hydrogen and Helium
spread in the space in an ever expanding volume.
 Condensation of such clouds made stars as sun.
 As gases condensed, spin of central region
increased to save momentum.
 At some points, the spin was so great that, gaseous
masses pinched off and thrown out by centrifugal
force, these formed the planets like earth.
 Similarly satellites were formed from planets.

THE PRIMITIVE EARTH
Earth originated as a rotating, red hot
(temperature about 5000 to 6000o C) gaseous
cloud of many atoms from sun.
At such a high temperature, every thing were in
free atomic phase.
As it moved far from sun, slowly lost heat, now
the atoms arranged due to gravity as per their
weights.
With cooling, heaviest atoms of Fe, Ni, Cu etc.
formed core, medium weight atoms as Na, K,
Mg, I etc. formed mantle, light metals formed
crust and lightest formed the atmosphere.

THE PRIMITIVE EARTH
The atmosphere of primitive earth was a
reducing atmosphere without molecular oxygen.
Absence of molecular is evident from :-
Sedimentary rocks are present on earth since
1.9 billion years ago. Their minerals are in a
low state of oxidation, than on these days.
Banded iron formations of older age are in
ferrous state, if oxygen would be present,
they must be in ferric state.
Early oceans do not have dissolved oxygen.
They organic compounds faced destruction in
presence of oxygen by oxidation.

ORIGIN OF MOLECULES & COMPOUNDS
Further cooling of earth by torrential rain favored
reactions. These reactions got energy from :-
Ultra violet rays from sun penetrating through
thin, ozone free atmosphere.
Electrical discharges as lightning during rain.
Heat from intense volcanic activities.
Oxygen being more reactive, combined with
Hydrogen to form water vapor.
Energy
Similarly sulfur react with hydrogen & many other.
Energy

ORIGIN OF MOLECULES & COMPOUNDS
These molecules react with themselves to form
simple compounds such as acids.
Energy
HOT WATER BROTH
The rain formed shallow hot seas.
Gradually they became larger oceans.
These oceans serves as medium for complex
chemical reactions leading to origin and evolution
of organic compounds.
So first life originated by abiogenesis and rest lives
by biogenesis.

ORIGIN OF ORGANIC COMPOUNDS
Due to property of catenation, carbon combined
with itself to form long chains.
It combined with hydrogen to form hydrocarbons
by energy from U. V. rays, lightning & volcanoes.
These hydrocarbons reacted with super heated
steam to form Aldehydes, ketones & acids.
They undergone condensation, polymerisation,
oxidation & reduction with ammonia & water in
hot water or hot dilute soup (Haldane) to form
carbohydrates, proteins & fats.
They had a tendency to form aggregated. Their
proximity led to more complex reactions.

COACERVATES
Proximity and more complex reactions among
organic compounds gradually got surrounded
by a fatty acid membrane. These were called as
Coacervates or living molecules by Oparin.
The membrane separated them from rest of
earth leading to more and more complex
reactions.
They formed nucleotides, nucleosides and
nucleic acids having property of auto-
replication.
Property of auto-replication led to biogenesis.

COACERVATES

ORIGIN AND EVOLUTION OF OTHER LIVES
First Living Cell / Protovirus – Coacervates
having nucleic acids became the first living cells.
Monerans & Protistans – Further complex life
form and reorganisation of protoviruses gave rise
to monerans and then protistans.
Origin of Autotrophism – Some monerans were
chemoautotrophs and some protistans were
photoautotrophs. They liberated free oxygen into
atmosphere, converting earth’s atmosphere into
oxidising one. It supported origin and evolution
of more complex life forms.
Fungi, Plantae & Animalia – In course of time
protistans gave rise to all these.