Darwin called this idea of certain traits being selected in order for an organism to reproduce sexual selection. in crickets and frogs, males call to attract mates and females are attracted to superior males by characteristics of their calls. how can this also be a disadvantage to survival of the species?

Remember that organisms within a particular environment all adapt in a simultaneous basis depending on the type of environment presented within them. This is part of Charles Darwin's theory of evolution when he observed animals in the Galapagos island. 

This survival instinct of the frog can be of disadvantage to it because other animals might be able to recognize their calls due to familiarity of this naturally occurring trait that they do. The frogs can now be more prone to predator attacks within its environment.

The answer is a because - is an direction