My views on objective morality

[Thumpalumpacus]

Not to mention that DNA's expression is greatly affected by the environment.

In the context of behavior, that too imposes some subjectivity on the process.

I don't think that's quite right.  If the DNA is interacting with the environment, and the conscious agency doesn't have control of this interaction, it's still objective.

I disagree. Example: you can have a genetic proclivity for addictive behavior, but because you were raised to despise drug users, your personal feelings kept you from being an addict. A result of environment, yet still intensely subjective.

Morality is no different. Altruism may be wired into our genetics at different levels for different individuals, but one's upbringing influences one's mental attitudes towards the morality of altruism. And when you invoke one's upbringing, you are introducing subjectivity into the process, because experiences do not matter until we mentally process them.