Answer:
it all depends on a particular pantheist. Pantheists are just people that use the word God to describe something else then then a deity that created the universe.
Pantheists may believe that we are the the product of evolution (and that life itself started with abiogenesis )
but they also might believe in myths
they might think that we came from wolfs stomach or anything else
pantheism just states that they call something else then a diety God.
other then that their believes can vary