These are excerpts and elaborations from my book "The Nature of Consciousness"
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Panspermia Comets are providing another
option: that life may have come from other parts of the universe. It was the
Greek philosopher Anaxagoras (fifth century BC) who first
speculated that life may have been dispersed as seeds in the universe and
eventually landed on Earth ("panspermia"). Spanish biochemist John Oro
(Comets and the formation of biochemical compounds on the primitive Earth,
1961) hypothesized that all building blocks of life were brought to Earth by
comets, a theory later popularized by the Belgian astrophysicist Armand
Delsemme. Organic material (from
water to methyl alcohol, and even forerunners of DNAs aminoacids) has been
found in the galactic clouds that float among the stars of our galaxy.
Interstellar matter seems to be rich in molecules that are needed to create
life. Trillions of comets wander through the solar system, and they
occasionally approach the Earth. They are soaked with the organic dust picked
up from the interstellar void. In other words, comets may have their own role
in the vast drama of life, sowing the seeds of life on all the planets they
intersect. Comets have been found to contain many if not all the ingredients
necessary for life to originate. (Incidentally, comets have been found to carry
ice, and no theory of the development of the Earth can account yet for the
enormous quantity of water contained in the oceans, unless the water came from
somewhere else). Also, left-handed aminoacids
(the kind that life uses) were found in the meteorite fragments that showered
Australia in 1969 (including some aminoacids unknown on Earth). If aminoacids are of
extraterrestrial origin and Wachtershausers mineral-based chemistry can
produce biological compounds, the chain that leads from dead matter to living
matter would be completed. But life is also capable of reproduction and
inheritance. Moreover, Wachtershausers model requires high temperatures,
whereas four of the five main
components of DNA and RNA (adenine, uracil, guanine, cytosine) are unstable at
those temperatures. Back to the beginning of the chapter "The Evolution of Life: Of Designers and Design" | Back to the index of all chapters |
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