In discussing the origins of life we are concerned with how the world and the multitudes of living organisms all came into being. There are only two accepted models used when speaking of origins. The first and most widely accepted viewpoint is that of evolution. Long time periods are needed because evolution works slowly with chance and natural selection guiding structural change. All life, as we know it today, emerged from single celled organisms which evolved over billions of years.
Evolution also mandates that geologic processes on earth have been uniform.
That is to say, there have been no sudden changes in geography or the environment here on earth. In order for evolution to be true, the fossil evidence must support the evolution model. The slow and gradual change necessary to bring about highly complex creatures should be clearly shown in preserved animal remains. During the billions of years that evolution has been operating there must be millions and millions of transitional forms of life. These transitional forms would be in the process of changing from one form to another.