There was no “first human” born from nonhuman apes just as there was no “first Italian speaker” born from Latin speakers - and for EXACTLY the same reason.
Latin did not become Italian in one day and for one speaker - it was an accumulation of differences that happened over a great deal of time.
Nonhuman apes did not become modern humans in one day and for one individual - it was an accumulation of differences that happened over a great deal of time.
Historic evidence indicates that Spanish and Italian were once the same language. What happened?
Genetic evidence indicates that rats and mice were once the same species. What happened?
The same thing in both cases. Separate populations accumulated differences until there was a fundamental divergence.
Still doesn’t make sense, surely a geneticist can look at rats and mice and document all the genetic differences between them.
Lets say for argument sake there are 100 total differences, and let’s say the argument you’re makings, is that there is this separate population of rats, each developed some of these traits individually, until the entire population gained all the traits over time and became mice. Surely, there is at one point, one individual member of the population that was the 1st to have all one hundred of these traits. That prior to that there were many with almost all of them, but none had all of them, until this individual mice came along.