The panspermia theory proposes that life originated outside of Earth and was transported here by meteorites or spaceships. It suggests that bacterial and microbial spores could have survived harsh space conditions like heat, cold, and radiation during travel and "seeded" life on Earth. While some meteorites contain amino acids similar to those produced in early Earth experiments, this theory does not fully explain how life originated either on Earth or elsewhere in the universe. It only describes how life may have appeared on Earth but not how it began.
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cosmozoic theory
1. BIO PRESENTATION
THE ORIGIN OF LIVING
THEORY
Created by:
1. Desiva Riana Putri (05)
2. Diah Ayuningrum (07)
3. Ima Miratunnisa (09)
4. Renolita Budiastuti (21)
Class:XII IA 4
2. The Theory of Panspermia (Cosmozoa):
Life from Outer Space (Interplanetary
Theory)
The Theory of Panspermia or Theory of Cosmozoa was
proposed by Richter in 1865 and supported by Arrhenius
(1908) and the molecular biologist, J.D./Watson, of the
DNA fame.
The Cosmozoa Hypothesis proposed that life was "brought"
to the primitive earth from cosmic bodies (in meteorites or
in spaceships). The primitive bacteria arid other
microorganisms "arrived" here as spores transported by
meteorites. Finding fertile soil here, they grew and then
evolved into the various existing forms. The theory is also
called theory of panspermia or spore theory.
It further assumes that the spores of organisms are
resistant and are not affected by the great amounts of
heat, cold, radiation that a meteorite encounters when it
travels in space.
3. Among meteorites investigated by scientists for signs
of life are the carbonaceous chondrites. They are
rocks containing 1 to 2% carbon by mass. Fragments
of chondrites, believed to be 4.5 billion year-old, were
collected from southern Australia in 1969. They
contain more than 80 amino acids. Some of them are
similar to those produced in Urey-Miller apparatus
(Fig. 23.8). They are not contaminated by amino
acids of the earth because they contain equal
amounts of D (dextro) and L (levo) isomers. A
majority of organisms on Earth make use of only L
isomers. Therefore the amino acids which reached the
Earth through meteorites like chondrites, could have
added to the "primitive broth". However, they
contributed very little.
This theory assumes that life exists elsewhere in the
Universe. It explains only the appearance of life on
earth. It does not explain its origin. It does not also
explain how life could have originated else-where.
5. This theory states that “the origin of
organisms in the earth comes from “life
spore” that comes from the outer spaces”.
6. The condition of the outer spaces is drying
with very cold temperature and the
presence of radiation. The condition like
this causes organisms can’t survive.
Finally “life spore” arrives to the earth