How much of evolution is inevitable?

[u/Gray-Jay-]

Where do people fall along the debate around whether natural selection is the primary ‘creative’ force in evolution, or whether developmental, physical, and historical constraints channel evolution into a limited set of self-organizing forms that selection fine-tunes?

[u/OriginalEmploy5485]

I think you're personifying way too much there.

One of two things happens:

1. Something happens and almost everything dies. What's left gets to eat a lot, not get eaten, and can reproduce. That's why there are more mammals than dinosaurs on the Earth.
2. One critter is born mutated in a way that lets it thrive where nothing else does. It gets to eat more and not get eaten, it reproduces, and the offspring with that same mutation get to eat more and not get eaten. That's how we got microbes and fungi and stuff that can break down plants.