A fish in a pond has longer protective spines than any other fish of its species. The spines keep the fish safe from predators. The fish has many offspring, which also have long spines. Which statement BEST describes what happened? A A mutation caused a beneficial change in the fish. B A mutation caused a harmful change in the fish. C Shorter spines caused a genetic change in the fish. D Longer spines caused a genetic change in the fish.
