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 3–5 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.

(4 points)
 
Short Answer Rubric (4 points)
Points Awarded	Criteria
4	
The answer is very clear.

The answer is fully supported by details.

There may be a few errors in grammar, usage, or mechanics. Errors do not interfere with meaning.

3	
The answer is mostly clear.

The answer is supported by mostly relevant details.

There are a few errors in grammar, usage, or mechanics. Errors do not interfere with meaning.

2	
The answer is somewhat clear.

Details are weak or not related.

There are some errors in grammar, usage, and mechanics. Errors interfere with meaning.

1	
The answer is not clear.

There are few or no supporting details.

There are many errors in grammar, usage, and mechanics. Errors interfere with meaning.

0	The question is not answered.

GPT-4o mini · Answer

I would expect to see more adaptations for salt tolerance in the freshwater snail population located at Location 2, as they experience higher salt concentrations (up to 0.5 ppt) compared to the population at Location 1, which experiences lower levels (0.1 ppt). Over time, snails in Location 2 may have individuals with genetic variations that enable them to survive and thrive in saltier conditions. Natural selection would favor these individuals, allowing their advantageous traits to become more prevalent in the population, leading to a greater overall ability to handle salinity changes in their environment.