Dawkins' book "Climbing Mount Improbable" is a great and easy read to introduce the idea of making something complex and seemingly designed for its purpose a much more probable thing to happen if broken into small changes over huge amounts of time. And it's like 30 years old, so probably outdated with more and better evidence now.

There is an old Youtube video by cdk007 (that's still up!) that tackles a related fallacy, where finding a watch on the beach implies a watchmaker because nothing complex can evolve. He created a simulation using watch parts and evolutionary rules to show complexity does arise with the right conditions and enough time.