Every cell, virus, plant, or animal mutation or characteristic is explained by Natural Selection.
It’s almost like there is some motivation for it to make sure life exists and survives. But why do anything at all? If there is a God then it makes sense that it was put in place for life to exist but if there is no God then why don’t we just have a universe of non-living matter?
Now this is speculation on my part, but I assume that any organisms that didn’t have this innate drive randomly present in their biology, they died off, so all that’s left now are the organisms with this drive.
So organisms that didn’t seek out reproduction at our earliest form of life, are dead and what remains are the organisms that randomly developed with this drive.