Humans have difficulties applying their “either-or” logic that they use for their own convenience of thinking to actual natural processes.
At what point does an embryo or a fetus become a human? Is there any point in its evolution when it suddenly turns into a human from one second to another? No, there isn’t. But humans can’t understand this. Anti-Abortionists and Pro-Life (= Anti-Woman) activists are the result.
At what point does an evolving species become a different species? When did the first dinosaur become a bird? There was no instant in time when that suddenly happened by the flip of a second, but our logic demands that we think that way. It is false.
Same with the difference between “living” and “dead”. We have invented a very rigid list of features that are required for a living being to be considered “alive”, but “dying” is a natural process. Thus there are still bodily functions going on in a corpse.
A human does not suddenly turn into an adult in the last second before midnight on his 18th birthday. We just made that rule up for our convenience.
This, effectively, is the reason so many people are unable to grasp the concept of evolution. Not only is it a process, but it usually takes so long that we are unable to observe it.
Sometimes we can trace it back, as was the case with Darwins Finches on the Galapagos Islands. There are many different species of Finches on the Galapagos Islands - all of which are certainly descendant from one population of one species of Finches that inhabited those islands long ago. They were, along with other animals he encountered there, what convinced Darwin of the process of evolution.
Just because humans have difficulty grasping a concept, doesn’t mean it doesn’t exist. Even “unthinkable” things can easily exist. Our inability to understand them doesn’t keep them from existing.
And even a universe without us in it would still exist and evolve. Regardless of the fact that we are not there to marvel at it and create stupid thought concepts like “either-or” logic that keep us from understanding it.
I find that a soothing thought.