A giant asteroid is hurtling towards the planet of technologically-sophisticated aliens. Physics allows us to predict the trajectory of the incoming rock as well as the effects of any possible mitigation attempts. But it doesn't recommend any particular course of action. Morality is out of scope for physicists.
Let's turn to biology. The aliens are survival machines: they respond to threats with countermeasures. The biologist predicts the aliens ought to deal with the problem. Morality has entered the building.
The aliens won't be calculating rationally what they should do to keep their genes in play (far too slow and unreliable in an open environment). They'll decide on their hopes, fears, sense of social cohesion and egalitarianism - all the stuff which worked over their evolutionary history. They'll encode these emotional norms as their morality.
Doubtless to get their advanced society to work at all (featuring capitalism, 'bourgeois democracy' and wars) the aliens will have to compromise their emotionally-grounded moral principles. They will invent hypocrisy and politics and muddled public intellectuals.
Evolutionary biologists will analyse all of this: no-one will be interested, however, in their rooting of morality in evolutionary science.
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Note: Just to clarify. Formal moral positions are relative, not absolute - that's why they can change (this point is never understood by many in the media who confidently believe their own elevated moral positions are normative across time and space). But morality can never stray too far or too long from its basis in human biological values; while our morality is rooted in our emotional value systems these themselves are complex, can be in conflict and can generate different moral conclusions.
Example: suppose there is an activity which some people indulge in which results in little harm but causes feelings of disgust in most other people (drugs and certain kinds of sexuality come to mind). This could lead to a moral repudiation of such activities and indeed, the people themselves (hate the sin, not the sinner is a step too far for most people).
But the 'sinners' naturally feel stigmatised and rejected, which violates another of our values: social solidarity, fairness and egalitarianism. So the moral fatwa may be reversed and the deprecated activity abstracted and rebranded ('a lifestyle choice') to damp down the majority's natural repugnance. Intellectuals and libertarians, who rather naturally lead with their intellects, and idealists, who lead with visions of social solidarity and empathy, are often found in the vanguard of such rebranding.
Such people are often, of course, found in politics and the media.
