In a population of crickets, all crickets make a “chirp” to attract mates at the same rate. Chirping also attracts predators, however. In one season, more than 50% of the crickets are eaten as prey as a result of chirping. In this simplified example, using only the information given, do you think this population will evolve by natural selection and why?

• A. Yes, because chirping increases reproduction, you can expect chirping to be more frequent in the future.
• B. Yes, because chirping attracts predators, there is a different rate of survivorship among crickets.
• C. No, because chirping attracts both predators and mates, the two effects will cancel each other out.
• D. No, because there is no initial variation in chirping, the population cannot change through natural selection.

Answer: (D)