Salt is dangerous to land snails. It will rapidly kill them. However, some populations of aquatic, freshwater snail have adapatations that allow them to live in a mix of salt and fresh water. This allows them to live in different parts of a river system. A group of scientists monitored salt concentrations in the habitats of two freshwater snail populations. They recorded the salt level as follows (in ppt, parts per thousand):

Question

Salt is dangerous to land snails. It will rapidly kill them. However, some populations of aquatic, freshwater snail have adapatations that allow them to live in a mix of salt and fresh water.  This allows them to live in different parts of a river system. A group of scientists monitored salt concentrations in the habitats of two freshwater snail populations. They recorded the salt level as follows (in ppt, parts per thousand):

Location 1 (Day 1):  0.1 ppt (morning), 0.0 ppt (afternoon), 0.1 ppt (evening)

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

In 4–5 sentences, describe in which population you'd expect to see more adaptations for salt water. Make sure to also explain how such adaptations would become more common in this population. Please answer simply, yet coherently, and intended for 9th grade.

GPT-4o mini · Answer

In Location 2, where the salt concentration reaches higher levels (up to 0.5 ppt), we would expect to see more adaptations for salt tolerance in the freshwater snail population. These adaptations might include specialized cells to regulate salt intake or ways to expel excess salt. Over time, snails that can better handle salt exposure are more likely to survive and reproduce, while those that cannot may die off. As a result, the traits that help snails survive in saltier environments would become more common in this population through natural selection.