"I think the theory of evolution can account for increased complexity just fine. "
Yup. Consider the slime mold, one of my favorite lifeforms on this planet. Sometimes it's nothing but single cells. Sometimes it aggregates and crawls across the ground like a slug.
Or, perhaps, the human egg. One cell. Joined by another cell. It grows into a human being. From simplicity to complexity...amazing.
Those who cannot see that the slime mold and the human do not have some relationship are truly blind. And still, we have both slime molds and humans on the same planet at the same time. Truly Evolution does not always involve increased complexity, although it can.
That would be the cellular kind like Dictyostelium, but I like the plamodial ones much better like Physarum.
One thing I did not expect to find when I joined FR was a fellow myxomycotophile.