What are some examples where apoptosis is normal for the proper development of an organism?

Recall that apoptosis is programmed cell death—think of it as the cell deciding to self-destruct. So you might ask yourself, why would a cell need to die?

Remember that, in the cell cycle, there are certain checkpoints where a cell may stop and ensure everything is going smoothly. If something went wrong, the cell could potentially become cancerous, in which case it is much safer for a cell to undergo apoptosis rather than risk developing cancer.

Another example would be in the immune system. When cells get infected, cells called cytotoxic t cells go around and force these infected cells to undergo apoptosis in order to reduce the spread of infection.

Hope this helps!

It is evolution, because we all have some of the same traits like eye color or shape or ears.