What rock pocket mouse trait were the scientists studying in the HHMI Biointeractive video?
Answer a. fur colour b. size c. number of offspring d. lifespan e. diet
The correct answer and explanation is:
Correct Answer: a. fur colour
The trait that scientists were studying in the HHMI Biointeractive video about the rock pocket mouse was fur colour. This research focused on understanding how natural selection drives changes in fur colour based on the environment.
Rock pocket mice live in the deserts of the southwestern United States. Most of the desert floor is covered in light-colored sand and rock, so mice with light fur blend in well and are less likely to be eaten by predators such as owls and hawks. However, in areas where volcanic activity has produced patches of dark lava rock, mice with dark fur have a survival advantage. On the dark rock, dark-furred mice are better camouflaged, making them less visible to predators.
The scientists observed that the distribution of fur colour among mouse populations matched the colour of the ground in their habitat. This pattern is an example of natural selection in action. Mice whose fur matched the background had a higher chance of surviving and passing on their genes. Over generations, the frequency of dark fur increased in populations living on lava rock, while light fur remained dominant on sandy terrain.
Genetic studies revealed that a mutation in the Mc1r gene was responsible for the dark fur. This mutation led to increased production of dark pigment, giving the mice their darker appearance. Importantly, the mutation did not affect other traits like size or lifespan, showing how a single genetic change can significantly impact survival based on environmental conditions.
This research illustrates how environmental pressures can lead to adaptations that enhance survival. It also shows the importance of genetic variation in enabling species to respond to changing habitats. Studying such traits provides real-time evidence of evolution and helps explain how species adapt over time.