Post by Bill on Feb 16, 2006 13:57:13 GMT -5
I found this really interesting, what do you guys think?
From
serendip.brynmawr.edu/biology/b103/f01/web1/baird.html
The Debate of Panspermia: Are We the Descendents of Aliens?
Alexis Baird
Panspermia is the theory tha stuff of life is everywhere and that we humans owe our genesis and evolution to a continual rain of foreign microbes. (1). The concept of panspermia has been around for centuries and was first proposed by the Greek philosopher Anaxagoras. (1) Since then, it has received varying amounts of endorsement from the scientific community. Although long shunned by most scientists, certain types of panspermia have recently gained support. While the prevailing theory for the origin of life is still that the first organisms formed spontaneously out of a nutrient soup during the early days of Earth and then evolved through random mutations and natural selection, the theory of panspermia should nonetheless be considered.
The type of panspermia most widely accepted is called weak panspermia or pseudo-panspermia. Weak panspermia is the theory that organic compounds arrived from outer space and added to the nutrient broth that spawned the first life. (3) The theory of weak panspermia is widely accepted and has extensive evidence to back it up. In 1969 a meteorite landed in Australia that was 12% water and contained traces of 92 amino acids. (9) This evidence points to not only the presence of organic compounds in outer space, but also the capacity of such compounds to reach earth. Also, millimeter arrays have detected the presence of complex organic molecules in star-forming clouds (9), further adding to the proof of organic molecules in space.
The second type of panspermia is called basic panspermia and can be defined as the presence of microbial life in space or on bodies such as comets or meteors that then reach a planet and start life on that planet. (3) Basic panspermia can then be broken down into three subcategories: radio-panspermia (cells travel by themselves and are propelled by light pressure), directed panspermia (microbial life was sent to earth in a spaceship by intelligent beings from another planet), and litho-, ballistic-, impact-, or meteoritic-panspermia (microbial life escapes from its home planet on fragments after a meteor impact). (3)
From
serendip.brynmawr.edu/biology/b103/f01/web1/baird.html
The Debate of Panspermia: Are We the Descendents of Aliens?
Alexis Baird
Panspermia is the theory tha stuff of life is everywhere and that we humans owe our genesis and evolution to a continual rain of foreign microbes. (1). The concept of panspermia has been around for centuries and was first proposed by the Greek philosopher Anaxagoras. (1) Since then, it has received varying amounts of endorsement from the scientific community. Although long shunned by most scientists, certain types of panspermia have recently gained support. While the prevailing theory for the origin of life is still that the first organisms formed spontaneously out of a nutrient soup during the early days of Earth and then evolved through random mutations and natural selection, the theory of panspermia should nonetheless be considered.
The type of panspermia most widely accepted is called weak panspermia or pseudo-panspermia. Weak panspermia is the theory that organic compounds arrived from outer space and added to the nutrient broth that spawned the first life. (3) The theory of weak panspermia is widely accepted and has extensive evidence to back it up. In 1969 a meteorite landed in Australia that was 12% water and contained traces of 92 amino acids. (9) This evidence points to not only the presence of organic compounds in outer space, but also the capacity of such compounds to reach earth. Also, millimeter arrays have detected the presence of complex organic molecules in star-forming clouds (9), further adding to the proof of organic molecules in space.
The second type of panspermia is called basic panspermia and can be defined as the presence of microbial life in space or on bodies such as comets or meteors that then reach a planet and start life on that planet. (3) Basic panspermia can then be broken down into three subcategories: radio-panspermia (cells travel by themselves and are propelled by light pressure), directed panspermia (microbial life was sent to earth in a spaceship by intelligent beings from another planet), and litho-, ballistic-, impact-, or meteoritic-panspermia (microbial life escapes from its home planet on fragments after a meteor impact). (3)