Yes, they are examples of adaptations of an ecosystem. Of course the million-dollar question is: are these the creation of an intelligent God or the fortuitous adaptations of happenstance? And I've been trying to establish that possibly God in His omnipotence could "iron out the worst parts," but in doing so would He also iron out the good parts? I have tried to argue that a dynamic system (which includes the worst parts) is superior to a static system (where the good necessarily goes out with the bad).
> Why can't NATO and the UN exist without Nazi Germany?
The reality of human nature tells us that without a causative common enemy, even alliances deteriorate into hostilities.
> Is slavery needed for Law, travel and trade? These things exist in modern societies that don't have slavery.
Slavery is not needed for law, travel, and trade, and yet even the modern human trafficking abomination is bringing forth human effort—compassion, networking, and legislation—to combat this boil on humankind.
> Why not make the universe more good by not having the unnecessary evil?
You're obviously free to disagree, but I think that God created the best possible world, and I thought I explained why.
- It's the only way we can truly be human rather than robotic
- It's the only way reasoning, science, and love can exist
- A dynamic world is superior to a static one
- A better plan on God's part is to share our suffering and redeem the evil rather than prevent it in the first place (which may not have been possible anyway).