Many species of venomous snakes have erythrophores and xanthophores in their skin, pigments that contribute to the formation of the snakes’ distinct colors. These pigments produce bright and intense hues, and because they are strongly associated with the venomous nature of the snakes, the vibrant colors generally serve as a warning to their predators. However, herpetologist Raymond B. Cowles and others have noticed that non-venomous species such as the San Francisco garter snake use iridophores in their skin to reflect and scatter light, creating the appearance of vibrant colors without the snakes necessarily having the pigments to produce them. These findings suggest that the appearance of San Francisco garter snakes may function as a deceptive warning to its predators.Choice C is the best answer. The text discusses the vibrant colors of venomous snakes that serve as a warning to predators; then, it mentions that some snakes without venom can also produce similar colors. This would mean that even non-venomous snakes, such as San Francisco garter snakes, can give a false appearance that serves as a warning to their predators.
Choice A: The text does not discuss any honest means used by San Francisco garter snakes, nor the snakes' reliance on pigments to warn their predators.
Choice B: This answer choice is irrelevant to the flow of thought in the text, as it does not discuss what herpetologists do or do not know about San Francisco garter snakes.
Choice D: The text does not indicate any difference between the vibrant colors of venomous snakes and those of non-venomous snakes.
✨ Expert's Tip ✨
Identify what the vibrant colors of venomous snakes serve as (“a warning”) and recognize that the colors will function in the same way even if the snakes are not venomous.