cosmozoic theory

1. BIO PRESENTATION THE ORIGIN OF LIVING THEORY Created by: Desiva Riana Putri (05) Diah Ayuningrum (07) Ima Miratunnisa (09) 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.

4. This theory states that “the origin of organisms in the earth comes from “life spore” that comes from the outer spaces”.

5. 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

6. This theory can’t accepted by many people.