Functional genetic sequences are too rare to have evolved from one another (Talk.Origins)

Claim CB150:

Evolution requires that protein sequences change to very different sequences, with all the intermediate sequences staying functional. But out of all possible sequences, functional sequences are extremely rare, so most functional sequences are highly isolated from each other. Using language as an analogy, one sentence cannot be changed to another by gradual changes such that all the intermediate changes are meaningful. It is highly improbable that random mutations could change one functional sequence to another.

Source:
 * Meyer, Stephen C., 2004. The origin of biological information and the higher taxonomic categories. Proceedings of the Biological Society of Washington 117(2): 213-239.

CreationWiki response:

This is not even a Creationist claim. It is a claim of Intelligent Design (not the same as creationism).

Since Talk Origins agrees that functional sequences are extremely rare (1 in 1011) that is not at issue. The real problem with this claim is that there is no reason to suppose that functional sequences are evenly distributed among the non-functional sequences, as is assumed by the claim.

Las secuencias genéticas funcionales son demasiado raras como para haber evolucionado unas de otras (Talk.Origins) Seqüências genéticas funcionais são muito raras para ter evoluído a partir de uma outra (Talk.Origins)