There are many theories where life came from, but none of them is proven to be the right one. The obvious theory that life originated on earth is not accepted by everyone. One reason of disbelief in this theory that life originated on earth is a lack of time. It was an early belief that life originated through a slow and long process (many scientists do not share this belief though), probably too short and too long for the time life had on our planet. Life must have been formed within a period of approximately 200 million years. "If we represent the whole Christian era - two thousand years - by one inch, the time available for the emergence of life could measure as much as 1.5 miles." Another theory called "panspermia" claims that life was created somewhere else, not on earth, and traveled to our planet via meteorites or comets. Another version of "panspermia" claimed by Francis Crick and Leslie Orgel is that life was brought to earth by a spaceship sent by a more intellectual species. This theory is called "directed panspermia". The last theory might be the least likely one, since there is no actual evidence for spaceships or species from other planets. The "panspermia" theory can not be disproved and it might be possible that life came to earth via a comet. Bodies like comets contain organic molecules which are similar to the molecules of living organisms, but most scientists say that reactions creating these molecules take "place out there". We can not find an answer for this question since neither theory can totally be proven. Supporters of the "panspermia" theory say that there was not enough time for life to originate. Supporters of the theory that life originated on earth can not prove that life did not come from outer space. The Christian theory that life was created by God is abstract and will not be discussed further in this paper. Personally I believe in the theory that life was born on earth. Six elements are needed to...
