I never heard anything from evolutionist side that when you die what happens then.
Sure you have, you've just don't understand what evolution means and thus equate it with atheism.
Just look up anything said by Pope John Paul II pertaining to the afterlife, he was an "evolutionist" and a Catholic. I think he has a few opinions about what happens after death.
Could someone elaborate on this theory.
There is no "theory" to elaborate on.
Did you present a theory, or a question...?
However, if you want to change your question to, What do
atheist believe happens after you die then my answer, as an atheist, is:
Life goes on without. As it is doing currently after all the people who died today, yesterday and everyday since then. Life goes on.
If you want to change your question further to, What happens to the
human body after you die? (again, this is directed to atheists). Then my answer, as an atheist, is:
it rots in the ground.
If you want to go one further, and ask, What happens to your
soul when you die? Then my answer, as an atheist, is:
I'm an atheist therefore I don't believe there is a soul.
"All great truths begin as blasphemies"
"I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your mouth."--Bill Hicks
"I never knew there was another option other than to question everything"--Noam Chomsky