Modern and Traditional Ethics
If there was a connection between historical and modern ethics and the development pattern of these two spheres of ethics, the connection could be adequately described as the status quo. That is to say, there really is no difference between the two. Ethical behavior remains ethical behavior and such behavior exists within human nature and transcends time, culture, history, the modern era, antiquity, etc.
There is an important philosophical question that needs to be posed here: is there much difference between traditional moral ethics and modern ethics? Human beings have evolved in a number of ways, but in many other ways they have remained the same. When it comes to moral and ethical values, virtually no society (past or present) seems to tolerate disrespect towards elders, stealing, adultery and murder. If there are such societies that do so, then they exist as radical departures from the norm.
Granted, there will be periods where social upheaval may challenge traditional norms of behavior (the cultural revolution of the 1960’s is one such example), but the challenges always maintain a certain epicenter. For example, what culture will consider stealing from the less fortunate as an ethical form of behavior. Of course, there are those who take part in such conduct, but they are anomalies and not indicative of any society as a whole. So, ultimately, the development of traditional ethics into modern ethics is really a non-development after all.