Some considerations in the evolution theory ?

If all life developed from simple single cell organisms, moving from the "maternal soup" to the present time, there are some logical considerations to ponder. The random genetic changes which account for the variations in animal life would not remain within the distinct catalogue of species, but would rather describe a "smear" of every imaginable form of life. Like snowflakes. The very survival of "species" within the framework of genetic experimentation seems to indicate something more than random evolution. Never have we caused one species to become another, nor have we observed such a phenomenon in our natural world.