Casually Explained is a great video series, here is Casually Explained explaining evolution. I suggest checking out the overarching YouTube Channel.
Evolution is the change of traits of over time, typically referring to the evolution of organisms. Modern evolutionary theory speculates the mechanics of evolution from the big bang (big bang theory), to how the physics of that work (quantum physics theory), to simple organisms becoming complex (endosymbiosis theory), to those complex organisms becoming species of plants, animal, fungi, etc (theory of evolution), to how “survival of the fittest theory” plays a role in that evolution, and more.
There are a number of theories pertaining to evolution (for instance the evolution of non-organic systems like social systems), and each should be judged on its own merit, however THE theory of evolution pertaining to the evolution of species is a pretty solid and respected scientific theory today over 150 years after Darwin wrote On the Origin of Species (his theory had holes, but modern theory has filled them in with experiment based science).
With that said, there are some aspects that we can never know, and in this space is room for spiritual and/or science-based theological thinking. Just don’t let faith-based arguments throw you off from what we do know from experiment in the lab, science isn’t meant to disprove faith, nor can faith disprove science, rather what we do know simply improves our ability to ponder deeper metaphysic and theological questions.
The state of nature is the state humans lived in before forming the first societies. By examining the state of nature we can better understand the implicit and explicit social contracts which govern societies.
Naturally occurring social systems are systems that naturally arise when societies form, such as politics, economics, mathematics, and language.