What is the meat in the spirit cage?

The fleshy soil in Linglong is a strange existence like wood and soil, which is formed by the human body rotting for unknown reasons. In the first episode, Ran Bing talked about "instantaneous decay" and the situation of infected female military doctors in PV. It seems that when people are infected, there will be two processes: instantaneous decay and slow decay.

In the first scene of revenant's entry into the spaceship, there should be a large number of human beings in the early stage of the catastrophe, and for some unknown reason, they immediately degenerated into paste. I judge this way because a lot of fleshy soil in the spaceship kept hugging and kissing relatives to say goodbye, which is a gesture of giving up resistance in the face of bottomless disaster.