Explain what it means to say that natural selection is not random

Natural Selection is not random because the organisms of a species that do not survive have a non-desirable genetic quality, a disease, injury, etc. This leaves the better organisms of a species to survive and reproduce, which creates a stronger and larger species.

X: plant material

Y: meat

Explanation:

Just look at the molars: One is obviously for eating meat, as the jaws in the front are sharp and can easily shred meat. One is for chewing plants, as it's molars are flat.