A brief introductory note - I am a long-time lurker and partner of Francesca, who often posts in MPSIMS but only lurks in GD.
It seems to me that people are confusing two notions, that of an immoral theory and non-moral theory. Evolution is a non-moral theory about the origin of biodiversity and makes no comment on the morality of action whatsoever. Therefore the theory of evolution is only morally bankrupt in the sense that it makes no commitment to morality in any way.
Evolution is a scientific theory: it offers only an account of the world in terms of observable phenomena and therefore cannot be criticised from a moral perspective.
This is a completely different question from the origin of our moral beliefs which may have developed with our evolutionary development. The standard account of the origin of moral beliefs is that higher primates developed compassion or “empathy” for their fellow primates because it benefitted both the individuals and the propagation of the species. These feelings of compassion developed into explicit codes of morality as social structures became more complex.
Contemporary moral philosopher Bernard Williams notes that it is a fallacy to judge the value of our beliefs on the method of their origin (the so-called genetic fallacy). For example, empathy is no less sincere for having been developed due to natural selection.
I’m not sure what you mean by this. I cannot see any logical tie between a moral theory being non-theistic (which is not the same as atheistic) and it being subjective. I’m not clear on how you drew such a conclusion. Kant argued that morality originated in the very nature of what it is to be a rational being and was inherently universal, i.e objective in the strongest possible terms, and his theory does not invoke God in any way. He went as far to say that we could legitimately evaluate the actions of someone such as Jesus Christ (assuming he was the Son of God) by his (Kant’s) moral system. Other philosophers who do not require God to justify an objective morality include Bentham, Mill, Aristotle, Confucius, Hume, and Hobbes.
Richard Holloway, the Bishop of Edinburgh, has written a book called Godless Morality, in which he argues that morality must come from a non-theistic basis.
Plato raised serious questions about the validity of invoking God in any question of morality, in the dialogue Euthyphro. I paraphrase: If an action is deemed right because God condones it, it must be for one of two reasons: either because God has a special insight into Right and wrong, or just because God wills it. If the first is true, then right and wrong are independent of God’s existence, if the latter then right and wrong do not apear to exist at all, and all morality is merely obedience to the Creator, and concepts such as suffering and justice go out the window.
This being the case, the only hope for a truly objective morality is one which does not bring in God at all.
Alex/Mr Fran