What is the meaning of human existence?
A human form serves the same purpose as every other physical form in the universe; a vehicle inhabited by a soul, (aka a ‘self’). Insomuch as a physical form is necessary to benefit from the wealth of lessons available only in this existence. Physical forms evolve, simply because evolving souls require ever more sophisticated forms to inhabit to support their improving abilities.
Many problems in the world are bred from the problem that humans think there IS a meaning to human existence. The truth (to me) is that we are here purely by chance (very small chance), and that we believe we are significant when we are not. The world would still be spinning, the stars would still be shining, if we were not here. Sad but true.
Humans evolved through the process of natural selection, in which the ones who were most fit to survive and reproduce lived and passed down their genes. Therefore their is no real meaning for human existence, human existence did not come forth for a reason but rather it came forth out of natural selection. This can be interpreted by some, however, that the meaning of human existence is to survive.