I'm something of a Mysterian myself, but find Derbyshire's argument from biology weak, principally because it is based on an interpretation of the phrase "made in the image and likeness of God" that strikes me as utterly jejune. Humans are not made in the image of God physically - God has no body, for God's sake! We are made in the image of God because we have a personality (or those of us who believe such believe it for that reason). And maybe other creatures are also made in the image of God to the extent that they have personality, too.
I also wonder about the built-in English prejudice against Catholics that he speaks of. What say you, Maxine?