It's not the selfish gene but the comparative advantage of a mutation that only after a few iterations automatically leads to the "winner takes all" principle. This process is well documented.

For my proper functioning in society*, I would very much like to understand why (bio-) logical complexity keeps increasing on earth. How is this information increase, this data negentropy, related to the overall process of entropy? Understanding this driver can perhaps help us to make better decisions.

* https://gl-10190.medium.com/debunking-degrowth-part-ii-aded18d44652