That's the beginning, yes, but evolution is touted as beginning with the first self-replicating system and includes aspects of randomness which are clearly also dependant on numbers.
Evolution is a materialistic explanation of life. It supposes some very unlikely things to occur in order for it to have brought about the numerous transformations from bacteria to humans. If there is any sort of an intelligent designer that created life, the more reasonable explanation is that these transformations were achieved by the intelligent designer who created life.
In fact, the evolutionist explanations of how life transforms itself from one lower species to a higher one have been constantly disproven by science. Essentially evolution is always trying to 'catch up' with science in order to 'explain away' the objections presented by new scientific discoveries. It thus keeps constructing more and more unlikely explanations for how evolution could have occurred.