Moral Tribes - What is Immoral Today May Be Moral Tomorrow - 1

I recently read Moral Tribes by Joshua Greene (https://www.amazon.com/Moral-Tribes-Emotion-Reason-Between/dp/0143126059).  It is a great book.  I recommend it to people seeking to understand how our societies my find ways to resolve moral differences.

However, I believe some content worthy of discussion was missing:

The content missing from the book is a section explaining that moral decisions are bound within an environmental context.  More specifically, they are not timeless.  Under utilitarianism, a society could eventually agree that abortion is acceptable, but later reverse that decision after technology improves to the point that a five day old fetus could be safely removed from its mother's womb and given a good life with a family that wanted it.   

Under utilitarianism, it is possible that when resources are abundant, a society should organize as the individualist Northerners do, as there is plenty to go around and a single Northerner can do little to harm the others.  That may have been best when Europeans first settled in the U.S.  But when resources are less abundant, or perhaps when the population has grown by so much that resources could be more efficiently allocated with a little central planning, then the collectivist approach of the Southerners works best.  In our society, some resources, such as water and Covid-19 vaccines, are scarce and benefit from a collectivist approach; while other resources, such as Internet cat videos, are plentiful and require little oversight to proliferate.  But the most important thought I am attempting to convey is that there is not a timeless moral truth or a "right way" that is independent of the environment.  Therefore what is "morally best" in one society and environment may not be "morally best" in another, and also that what is "morally best" for a society can change over time.