Antonin Scalia wrote one of the most bizarre concurrent opinions in the history of the Supreme Court in the decision that corporations could not patent human DNA.
Concurrent opinions are reserved for justices who agree with the ultimate judgement but disagree on some fine point of law within the judgement. Scalia didn't do that. He wanted preserved in the history of the court for posterity that he did not understand nor believe in molecular biology.
It was an odd thing to do. Was he slyly chiding his colleagues? Was he saying the court should have avoided the case because none of them understood the science? It's the kind of arrogant SOBish thing he would do. But I don't think that's it.
Scalia has based his entire career on the theory that neither man nor science has changed in the last 250 years. Molecular biology is one of those newfangled sciences that didn't exist when the Constitution was written. Scalia, quite simply, refuses to believe in it. He put that in writing because in some future case, probably having to do with gay rights, he intends to rely on denying the basic facts of biology.
Or, Scalia is just a raving loon.