On Objective Morality 2.0

Instead of imagining humans evolving morality, like fingers. Imagine the concept of morality as the best methods for keeping [high] civility [and well being] within large groups, and evolution forcing humans to adapt a sense of morality so as to better organize ourselves. Take for example, flight. There's the concept of flight and there's the evolution of flight. In order for something to be able to fly, animal or otherwise, it needs to be light weight, aerodynamic and be able to catch air so as to fall more slowly or get lift. Evolution needn't have evolved flight in animals for the concept of flight (or aerodynamics) to exist as a natural phenomenon. Evolution can however adapt certain animals to take advantage of this phenomenon to improve the survival chances of a species.  

Humans may have evolved a sense of morality; evolution's best efforts at allowing us to grasp the better and worse methods at organizing large groups so as to allow individuals to prosper and stay physically and mentally healthy.  

"if we'd evolved into a society where rape is considered fine". To keep with the flight analogy, this is like saying if birds had evolved methods of flying that basically just involve falling. Well, it simply isn't flight and it simply isn't moral because a society where rape is fine is far from the best way of organizing large groups while ensuring the prosperity of every one involved.

 

Somewhat related musings:

Morality exists on the "is" side of the is-ought gap.
Examine morality and determine how it exists as part of reality.
Maximizing the wellbeing of conscious creatures both in the present and future as a metric for morality.

Wellbeing as a measurement of physical and mental health.

• Physical health can be measured through a medical check.

• Mental health can be measured by qualified psychologists.

consciousness: https://plato.stanford.edu/entries/consciousness-neuroscience/#AcceConsPhenCons 

Investigate the illusion of free will and its relationship to the causality of our moral decisions.