I prefer the following analogy:
Student A turns in his term paper, which his professor notices is remarkably similar to a term paper turned in by Student B the prior year. In fact, it appears identical to Student B's term paper except for a few opportunistic changes: Student A's name at the top, the current course's recommended texts in the bibliography, and so on. Most curious are the presence of certain typographical errors in Student A's paper which just so happen to be exactly the same errors as occur in Student B's paper.
If Student A claims that his paper is a completely independent creation, who would buy that?
Creationists want us to believe that what we know about the DNA molecule and reproduction should tell us nothing about the relationships between separate species. They want us to believe that similarities among genomes of many dissimilar species, even identical mutations in the exact same spot in the genome, is just as forceful evidence of independent creation as of common descent.
But who's buying that?
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The dark nursery of evolution is very dark indeed.
Brad McFall