Hurry! organisms must have variation with a population in order for natural selection to occur. a)a frog living in a pond is eaten by a predator, while others in the same population survive. b) a snake living in a desert produces more offspring than other snakes in the same population c)some rabbits living in a forest have short, spotted ears, while others have long white ears. d) some birds living in a grassland eat less than other birds who eat the same food