Let's assume that Mother Nature is actually nature itself. K? K.Science and the copy and paste children here, claim natural selection. They don't even have a clue. There is no such thing as natural selection other than some made up BS
Ask the children to give you an example of natural selection.
A herd of deer headed to their traditional winter feed grounds. The winter is especially harsh that year and half of the herd dies during the winter.
Some died from starvation. Some died from exposure, some died from old age. And, some died from a combination of those things.
The deer which survived that harsh winter are the ones which were "naturally selected" by Mother Nature herself.
Those deer had ample enough fat stores in their bodies, had adequate shelter to wait out the cold and the storms, and were young enough to endure hardship long enough to make to the new grass shoots of spring.
What else you wish explained to you?