Final answer:
Dark-colored snakes in a light sand desert would likely evolve to become lighter in color over time due to natural selection, as they would be less visible to predators and have a higher survival rate. Over time, the genes for lighter coloration would become more common in the population due to this selective advantage.
Step-by-step explanation:
Natural Selection and Color Adaptation in Snakes
According to the concept of natural selection, dark-colored snakes in a light sand desert would likely evolve to become lighter in color over time. This evolutionary change would occur because lighter-colored snakes would be less visible to predators in the sandy environment, thus having a higher chance of survival and reproduction. The visibility of the dark-colored snakes against the light sand would make them easier targets for predators, leading to higher predation rates. Over time, the genes for lighter coloration would become more prevalent in the population as these snakes would have better camouflage and thus higher survival rates.
In contrast, dark-colored snakes would not become more common nor would they be unaffected by their color in the desert setting, as their poor camouflage would not aid in evading predators. Additionally, it is unlikely that the dark-colored snakes would become extinct solely due to their coloration, as there could be other factors at play, such as behavioral adaptations that could help some individuals survive even if they are poorly camouflaged.
Theoretically, were a fierce predator to be introduced that specifically preys upon these snakes, natural selection could lead to the evolution of other defensive adaptations such as toxins or behavioral changes, perhaps alongside the lighter coloration, but these would be secondary to the immediate selective pressure of camouflage against the sandy backdrop.