Consciousness!
The Universe itself a life, with several lives being the part of it.
Every life, including the universe, must be the result of the consciousness of a conscious entity.
While the conscious being and consciousness must the real, the life that it generate are not.
This is because every life is transient.
Then what is there in the universe?
Conscious entity.
The conscious entities generate consciousness when they come alive or energised. The act of (perception of) Conscious entity is called “Consciousness.”
It is like a light-bulb glow when the electric current pass through it.
The perception of every one of the lives about the lives and objects in the Universe will vary with the conscious entity that perceive.
Even among lives of the same specie the consciousness varies.
At the same time, the consciousness of lives belonging to a specie are, by and large, comparable.
In a given plane, the life-span of species, do vary but within a reasonable range. But between the planes, the Space-time of lifes generated by conscious entities could be several thousand times of that from lower planes.