"separation of yin and yang"

[mushuporkert]

I have heard this phrase mentioned in the context of both tongue and pulse diagnosis and am looking for some clarification on what this "separation" actually means. I am having a hard time imagining a separation of complimentary opposites occurring in nature.

[Tai Yuan]

The intermixing of yin and yang, together, allow life to thrive.  In living beings we see the descension of celestial energy and the ascension of the terrestrial energy exhibited by the channels themselves - yin channels ascending, yang channels descending.  This is the Tai Ji Tu.  http://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Esoteric_Taijitu.svg/463px-Esoteric_Taijitu.svg.png

Yet yang's nature is to ascend, yin's nature is to descend.  So in biota, living things, we see the opposite happening.  Until there is disease. 

The separation of yin & yang ultimately points to death.  Yin returns to the earth, and yang to the heavens.