What is the actual process by which academic ethics change? Some of the answers to my question Are academic ethics global or local? indicate the possibility that academic ethics themselves (rather than just laws and policies affecting academics) may change over time.

What is the actual process by which academic ethics may be altered? More specifically, is the process:


Top-down, in which regulatory agencies, funding sources, legislatures, etc. push down new rules onto academics, who are expected to internalize them as normative? (e.g. "Please take note that fooing the bar is now against our Code of Ethics. If you do not cease all bar fooing activity by the end of the fiscal year, your grant will not be renewed.")
Bottom-up, in which written codes of ethics, laws, funding guidelines, etc. are modified as time goes on to match popular consensus? (e.g. "According to our recent surveys, 95% of academics and 82% of the general public Agree with the statement 'It should be considered unethical when academics foo the bar.'. For the 2020 fiscal year, we should make not fooing the bar a requirement for funding.")


The question can alternately be phrased as asking about the nature of academic ethics themselves - whether the "true state" of what is ethical and what is not is part of written rules of academia (and thus reflected in applicable policies, laws, procedures, etc.), or part of the unwritten rules.
I'm sure both processes happen.  

The latest Common Rule for human subjects is a great top-down example.  https://nexus.od.nih.gov/all/2019/01/07/nih-implementation-of-the-final-rule-on-the-federal-policy-for-the-protection-of-human-subjects-common-rule/ 

This process reinvestigated human  subject ethics in the context of modern-day genetics.  It almost required specific informed consent for the collection of deidentified tissue, with periodic renewals of consent and the ability to yank consent.  Picture what that would do to say, developed perpetual cell lines used for research!  MANY universities were waiting anxiously to see what would come out of that process and there were very large discussions on how such requirements would be met.  We even modified our CLINICAL operations to accommodate anticipated changes that never happened!!

I say this is a great top-down example because the ethics are, and still remain, hard to figure out.  Stakeholders had to get together and form consensus.  Nobody knew what the outcome would be when the process started.

As an example of bottom up, there is the example of neurosurgeons that now require sham surgeries before adopting a new procedure. This fell out of human fetal tissue transplant attempts. ncbi.nlm.nih.gov/pmc/articles/PMC1733639  There is no relevant reg, but I'm sure this is now incorporated into RSRB discussion.