Darwin argued that natural selection would never cause a species to evolve a trait that benefits another species at a fitness expense to its own species. a study of egrets in florida found that parents eject their own chicks from their nests, and this behavior feeds alligators living in the swamp below the nests. this steady supply of food improves the health and condition of the alligators. in view of darwin’s logic, what are two hypotheses that might explain why the egrets perform behaviors that benefit alligators?