Salt is notoriously dangerous to land snails; however, some populations of aquatic, freshwater snail have brackish (or a mix of salt and fresh water) water adaptations and live in different parts of a river system. A group of scientists monitored salt concentrations in the habitats of two freshwater snail populations located nearby and recorded the salt level as follows (in ppt, parts per thousand): Population 1 (Day 1): 0.1 ppt (morning), 0.0 ppt (afternoon), 0.1 ppt (evening)

Population 2 (Day 1): 0.3 ppt (morning), 0.5 ppt (afternoon), 0.2 ppt (evening)

In 3-5 sentences, 1) describe in which population you'd expect to see more adaptations for salt water and 2) explain how such adaptations would become
more common in this population.