A species of cactus has spines. How would biologists explain how a species of cactus with spines evolved from an ancestral cactus species without spines ?

Which of the following is most likely the result of an organism having lipids in its body a) water cannot be absorbed through the surface of a leaf b)human eats fruits to get a quick source of energy c) a sheep sleeps for more hours in the winter d) a warm river is filled with fish and algae