What does it mean that “HIV causes AIDS” is true?pic.twitter.com/oOIxKn2D2P
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“Related” or “unrelated” is meaningful only relative to an implicit reference class. HIVs are “related” relative to lentiviruses
The most recent common ancestor of HIV-1 and -2 may be millions of years ago; no one seems to have a good estimate
“Paraphyletic,” interestingly, eliminates the need for the implicit reference class; it’s absolute and not relative in that way
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