Evolution
1. The atomic phase- Easy earth had innumerable atoms of all those
elements, e.g. Hydrogen, oxygen, carbon, nitrogen, sulphur,
phosphorus etc. which are essential for formation of protoplasm.
2. Formation of simple molecules- Free atoms combined to form
simple molecules such as Hydrogen, Nitrogen, Water vapour,
methane. Hydrogen atoms are most numerous and reactive
primitive atmosphere (without free oxygen) unlike the present
oxidising atmosphere (with free oxygen).
Hydrogen atom also combined with nitrogen, forming ammonia, so
water and ammonia were probably the first molecule of primitive
Earth.
3. Formation of simple organic molecule (monomers)- The early
simple organic molecules interacted and produces simple organic
molecules such as simple sugar e.g. ribose, deoxyribose, glucose
etc.,Nitrogenous bases (e.g. purines, pyrimidines) Aminoacids,
glycerol fatty acids etc.
Torrential rains must have fallen, as the water rushed down, it
must have dissolved away and carried with it salts and minerals
and ultimately accumulated in the form of oceans. Thus oceanic
water contained large amount of dissolved ammonia, methane
nitrides, carbides, various gases and other elements.
Some external sources must have been acting on the mixture for
reactions. These external sources might be (i) solar radiations such
as ultra violet light, X-rays etc(ii) Energy from electrical discharges
like lightning (iii) high energy radiations are other sources of
energies (probably on primitive Earth). There was no ozone layer
in layer in atmosphere. A soup like broth of chemical formed in
oceans of the early earth from which living cells are believed to be
have appeared, was termed by J.B. Haldene (1920) as 'preboitic
soup' ( also called as hot dilute soup.
Thus the stage was set for combination of various chemical
elements. Once formed, the organic molecules accumulated in
water because their degradation was extremely slow in the water
because their degradation was extremely slow in absence of any
life or enzyme catalyst.
1. The atomic phase- Easy earth had innumerable atoms of all those
elements, e.g. Hydrogen, oxygen, carbon, nitrogen, sulphur,
phosphorus etc. which are essential for formation of protoplasm.
2. Formation of simple molecules- Free atoms combined to form
simple molecules such as Hydrogen, Nitrogen, Water vapour,
methane. Hydrogen atoms are most numerous and reactive
primitive atmosphere (without free oxygen) unlike the present
oxidising atmosphere (with free oxygen).
Hydrogen atom also combined with nitrogen, forming ammonia, so
water and ammonia were probably the first molecule of primitive
Earth.
3. Formation of simple organic molecule (monomers)- The early
simple organic molecules interacted and produces simple organic
molecules such as simple sugar e.g. ribose, deoxyribose, glucose
etc.,Nitrogenous bases (e.g. purines, pyrimidines) Aminoacids,
glycerol fatty acids etc.
Torrential rains must have fallen, as the water rushed down, it
must have dissolved away and carried with it salts and minerals
and ultimately accumulated in the form of oceans. Thus oceanic
water contained large amount of dissolved ammonia, methane
nitrides, carbides, various gases and other elements.
Some external sources must have been acting on the mixture for
reactions. These external sources might be (i) solar radiations such
as ultra violet light, X-rays etc(ii) Energy from electrical discharges
like lightning (iii) high energy radiations are other sources of
energies (probably on primitive Earth). There was no ozone layer
in layer in atmosphere. A soup like broth of chemical formed in
oceans of the early earth from which living cells are believed to be
have appeared, was termed by J.B. Haldene (1920) as 'preboitic
soup' ( also called as hot dilute soup.
Thus the stage was set for combination of various chemical
elements. Once formed, the organic molecules accumulated in
water because their degradation was extremely slow in the water
because their degradation was extremely slow in absence of any
life or enzyme catalyst.
