For well known reasons, having even one complex creature arise via combinations of mutations and "natural selection" would be a probabilistic miracle, i.e. an absolutely zero probability event come to pass.
The problem is that a reasonable person might could buy off on some sort of a theory which demanded one such probabilistic miracle in the whole history of the universe but evolution requires that every creature which ever walked, swam, or flew on, under, or over the Earth arise in such fashion, which is basically an endless sequence of probabilistic miracles. That basically stands everything we know about modern mathematics and probability theory on their heads.
The Earth is commonly supposed to be three or four billion years old and the universe itself about 20 billion years old. Nonetheless entirely reasonable calculations have shown that even if there was such a thing as mutation and selection creating our present biosphere from inorganic materials (hint, there isn't such a thing), it would demand quadrillions or quintillions of years.
One statement of the actual time frames demanded for evolution is here.