Hi Derek,
I strongly agree that outsiders are needed in philosophy of mind.  And I definitely appreciate your pointed questions about naturalistic claims about the mind.  I agree with you that claims about the evolution of consciousness are not justified.  Part of the problem, as you suggest, is that there is such wide disagreement about the mind.  As a result, we are not even sure what evidence for or against such claims would even look like.  What for one person looks like evidence that apes or pre-human ancestors had limited consciousness seems incoherent to another person who thinks that consciousness is all or nothing.  We don't understand the significance of the mirror test.  It is not at all clear to me that more empirical tests are needed tor resolve the issues.  I believe that our "experts" on consciousness are in over their heads.  Consider the following question: What assumptions, if any, do we make about consciousness when we assume that empirical science is the appropriate methodology for studying it?  I see very, very little good discussion on this.  The exceptions tend to prove the rule.  For example, Stanley Cavell was good on these sorts of questions, but he would sympathize with you and me here.  Another exception are the logical positivists like Carnap and Schlick.  Despite their craziness, the logical positivists took seriously the notion that science places constraints on what it makes sense to talk about and they attempted to reflect on those constraints.  In my paper on the inverted spectrum, I draw out the implications of their reflections.  The paper is not written in my own voice.  I disagree with the logical positivists.  I do, however, believe that we need to expand the discussion to include those who reflect on the methodology of science in a critical and systematic way, which Carnap certainly did.  That is the spirit in which I wrote the paper.  I think Carnap's questions are excellent.  His answers I disagree with.