The brackish water adaptation is clearly necessary because the aquatic snails need to live in an environment in which the river system has a higher quantity of salt than what land snails can take. I can determine that the environmental factors influenced the inherited adaptations because the second population has a higher salt concentration in their habitat compared to the initial population.
Cats and dogs are both mammals because they have hair, are warm-blooded, and nourish their young with milk. Dogs and cats are distinct species, incapable of producing offspring together because of the many differences in their genome.
