What is reterograde evolution? Please explain with examples. How it is associated with human evolution?
The only time I've heard the phrase "retrograde evolution" was in a book about Indian/Buddhist political and spiritual philosophy of history. The idea with retrograde evolution is not quite the opposite of progressive evolution. Retrograde evolution takes humanity through a mental/physical decline to the point where a necessary revolution is needed, or more specifically, a decline to the point where a social/political (dharma) order is necessary. I'm not sure if this kind of retrograde evolution is an evolutionary anomaly, something unfortunate or unexpected, or if it is just part of the cyclical nature/culture of human evolution.
'Devolution' is the term most often used to mean the opposite of evolution. Retrograde evolution must mean something more along the lines of 'two steps ahead, one step back.' Something more like an apparent regression but one meant to be a progressive step in the long run.
With respect to biological retrograde evolution, the examples I've found both had to do with the loss of wings: insects and some birds losing the ability to fly - which could be good or bad depending on how they adapt to the changes or how favorable the environment is to those changes.
With respect to human evolution, the example I found was the story of Vrishabha and Bharata in the development of social order, which resulted from the loss of strength of medicinal plants. The idea here is that a social order was needed to help the people survive - as the people were lost, having become too dependent on things like wishing trees. Analogous to today: people becoming too dependent on technology.
I also read the phrase retrograde revolution describing the French Revolution; and it would make sense to me that any kind of Marxist revolution would fit this description. It seems to me, that in natural and cultural cases, retrograde evolution is essentially one of two things: a necessary step back in order to sustain a long term progression, or an intended step forward which had some unintended step(s) backward.