Can evolutionary theory provide evidence against psychological hedonism?

Sober and Wilson (1998) argue (1) that neither psychological evidence nor philosophical arguments provide grounds for rejecting psychological hedonism, but (2) evolution by natural selection is unlikely to have led to such a single source of motivation. In order to turn their piecemeal discussion of (1) into a serious argument, Sober and Wilson need a general procedure for mapping alternative accounts of motivation into egoistic hedonistic accounts. That is the only way to demonstrate that there will always be an available hedonistic account no matter what the psychological evidence. But such a general procedure, if available, must block their argument for (2). So, the more persuasive the case for (1), the less persuasive the case for (2).