Evolutionarily it is a REASON why the desire evolved that way, but it is not the same thing as what the person FEELS, on a conscious or subconscious level. If you claim that evolutionary reasons are a person's 'true preferences', then it follows that a proper morality should focus on maximising everyone's relative shares of the gene pool at the expense of, say, animals rather than anything else.
EDIT: I'm also curious about your response to all of my arguments.
If you claim that evolutionary reasons are a person's 'true preferences'
No, of course not. It's still wrong to say that deterrent is nowhere in their brains.
Concerning the others:
Scientific inquiry percieves facts which are true and useful except for goals which run directly counter to science. Morality perceives 'facts' which are only useful to those who wish to follow a moral route.
I don't see what "goals which run directly counter to science" could mean. Even if you want to destroy all scientists, are you better off knowing some scienc...
Sam Harris is here offering a substantial amount of money to anyone who can show a flaw in the philosophy of 'The Moral Landscape' in 1000 word or less, or at least the best attempt.
http://www.samharris.org/blog/item/the-moral-landscape-challenge1
Up to $20,000 is on offer, although that's only if you change his mind. Whilst we know that this is very difficult, note how few people offer large sums of money for the privelage of being disproven.
In case anyone does win, I will remind you that this site is created and maintained by people who work at MIRI and CFAR, which rely on outside donations, and with whom I am not affiliated.
Note: Is this misplaced in Discussion? I imagine that it could be easily overlooked in an open thread by the sorts of people who would be able to use this information well?