Coincidence can NOT be the cause of functional mutation in proteins. There you go, Charles. There is no alternative for the cause of macro-evolutionism apart from mutations. In all cases this leads to a loss of function. Original species are richer in genes than mutated species.
Variation is caused by loss of genes.
Variation is always variation on a theme, hence 'typological differentiation'. Similarities are NOT proof of common ancestry, but of similar functions. Scientific canon is often politically motivated and, as we know from history, usually disproven at some future date. Evolution can move along quite nicely without an assumption of mutation, especially given sexual reproduction which increases genetic variability. Variable descendant leaving success influences the species and the gene pool.