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.
(4 points)
1) Based on the salt concentrations recorded, Population 2 would be expected to have more adaptations for salt water. This is because the average salt concentration in Population 2's habitat is higher than that of Population 1.
2) The snails that are better adapted to salt water in Population 2 would have a higher chance of survival and reproduction compared to those in Population 1. This is because they are better suited to their environment and can cope with the higher salt concentrations. Over time, these salt-adapted snails would pass on their advantageous traits to their offspring, increasing the prevalence of salt-water adaptations in the population.
1) Based on the salt concentrations recorded, it can be expected to see more adaptations for saltwater in Population 2. This is because Population 2 experiences consistently higher salt levels compared to Population 1 throughout the day.
2) In Population 2, the snails that have adaptations for saltwater would have a higher likelihood of survival and reproductive success. These adaptations could include physiological changes that allow the snails to handle higher salt concentrations, such as specialized ion pumps to regulate salt intake or excretion. Over time, these adapted snails would be more likely to pass on their advantageous traits to the next generation, leading to the increase in the frequency of these adaptations in the population as a whole.
1) Based on the salt concentrations recorded, you would expect to see more adaptations for salt water in Population 2. This is because Population 2 is exposed to higher salt concentrations (0.3 ppt in the morning, 0.5 ppt in the afternoon) compared to Population 1 (0.1 ppt in the morning, 0.0 ppt in the afternoon). Higher salt concentrations provide a stronger pressure for the snails to adapt and develop mechanisms to tolerate and survive in brackish water.
2) Adaptations for salt water would become more common in Population 2 through natural selection. Snails that have genetic variations or traits that enable them to better tolerate salt concentrations have a higher chance of survival and reproduction in the brackish water environment. Over time, these individuals will pass on their favorable traits to their offspring, increasing the frequency of adaptations for salt water within the population. This process is known as natural selection, where individuals with advantageous characteristics are more likely to survive and pass on their genes, ultimately leading to changes in the population's genetic makeup.