Well the theory of evolution does nothing to explain the origin of life itself; The chances of the ten to twenty required amino acids to collide together in tFhe right way to form just one enzyme is one in ten to the power of twenty. For all the enzymes required to make a protein the chances or one in ten to the power of forty thousand (even less likely than the cosmological constant allowing the universe itself to exist). Not only that but they are then required to be held together in "the primordial soup" long enough for the same thing to happen to make another protein. Ultimately this must happen millions of times in order for a single strand of DNA to form. These facts are all in Charles Thaxton, Walter Bradley & Roger Olsen's 1984 book "The mystery of life's origin".
Let's suppose just for a moment that all of these unlikely things happened. One would assume it would take billions of years to happen. However, there is evidence of life existing on Earth as early as 3.8 billion years ago. Very shortly after the sun formed (about 25 million years). Given the time scale, it is estimated that by the time a single cell would have been formed naturally and accidentally the sun would be nearing its end. However, the sun is still very young. So if this "accidental cell" was formed, it has done so several billion, billion, billion, billion times faster than probability says it should. Once again the chances of it actually doing this are too small to even calculate.