We all are humans, this belief is ignorance. This is darkness.
We all are spirits who are presently in human form, this belief is knowledge, this is light.
We might be insects tomorrow or birds or animals or trees or heavenly beings or demons and ghosts or may mingle into salvation or sleep forever stage.
This is real knowledge. This is Truth.
A person who knows this Truth should be identified as Wise. Rest all who do not believe or do not understand this truth and ponder about Ape-man theory, Evolution and other scrap and misguiding theories are all Fools or ignorant. Never ever trust them. They are the blinds guiding the blinds.
Keep distance from such fools and ignorant ones and associate with the wise who knows that we are spirits. We are temporary humans but our afterlife will determine our long term form, whether human or demon or heavenly being.
Arya culture or Hindu culture is bent on upgrading your spirits to higher heavenly forms for millions and millions of human years. However even Goddess Gayatri claims that some say the God of Heaven will attain a form of Lotus afterwards because of engaging in too much sensual enjoyments. This means even immortal ones are not having a fixed form forever.
So nothing is eternal including the Gods in this Nature.
In front of eternal time, everything is changeable. Only change is constant in this universe.