Not at all; given what we know about genetics, mutations, and the genomes of numerous species alone, evolution is the natural conclusion.
Or, perhaps to ask more specifically: Where, exactly, am I assuming evolution in my analysis of the evidence? Do you have a problem with mutation? With chromosomal fusion? Please, do be specific.
Far from it. We have yet to see any beneficial mutations. All seen so far have been either neutral or detrimental. Also, the type of mutations necessary for evolution would have to add new pieces to the DNA to create new traits (All known mutations are just corruptions of the DNA an organism already has and not additions to the DNA). I would love to see an explanation for how this is supposed to happen.