Highly improbable is maybe a better choice of words. But yet possible because here we are talking about it and it only took about 4.5 billion years. Here is a good link-http://en.wikipedia.org/wiki/Evolution
Science today does not have the answer for the origins of life but scientists are getting very close. But this does not mean we should put superstitious beliefs in its place in the mean time because that is not a better explanation of life's origins. Many centuries ago deities were used to explain natural phenomenons because of the lack of information and technology to measure and explain these phenomenons. Today in the 21st century things are explained alot better through scientific means.
http://en.wikipedia.org/wiki/Darwinism this is an interesting link also.
peace
Doug
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