From New York Times op-ed, “Natures Case for Same-Sex marriage”

“A wide, living rainbow arcs across the natural world. Diversity rules in sexuality, just as it does in the rest of biology. This natural variety does not provide ready-made moral guidance. But to claim that the only natural forms of sex and pair bonding occur between unambiguous males and females is to ignore the facts of human biology. Let those who wish for marriage equality to be ‘founded in nature’ take note: the view outside  the Supreme Court is full of life’s beautiful sexual variegation.” 

David George Haskell, Professor of Biology at Sewanee: The University of the South