[anentropic]

> but equivalently fit ways, then given the stochastic nature of evolution this is almost guaranteed to happen

I would probably put different commas:

"but equivalently fit ways then, given the stochastic nature of evolution, this is almost guaranteed to happen"

I suggest this based on intuition alone, but I believe the principle is: http://www.grammar-monster.com/lessons/commas_for_parenthesi...