Marsupial moles are blind due to the evolutionary adaptations they have undergone over time. These adaptations have led to the reduction of their eyes to vestigial lenses under the skin. This means that their eyes have lost all or part of their original function.
The reason behind the blindness of marsupial moles can be attributed to their unique lifestyle and habitat. These moles are burrowing mammals that spend the majority of their lives underground, digging through the sandy soils of the Australian desert. As a result, they have adapted to their subterranean lifestyle by developing certain characteristics that are advantageous for life underground.
One of these adaptations is the reduction of their eyes. Since they spend their lives in the dark tunnels they create, there is little to no use for well-developed eyesight. In fact, having large, exposed eyes could be a disadvantage as they are vulnerable to injury from the abrasive particles in the soil. Therefore, over time, the eyes of marsupial moles have regressed and become non-functional, appearing as small, vestigial lenses under the skin.
Another adaptation related to their blindness is the absence of external ears. Instead of having visible ears like many other mammals, marsupial moles have a pair of tiny holes hidden under their thick hair. This helps to further protect their delicate ear structures from the harsh environment they inhabit. By not having visible ears, they reduce the risk of soil particles entering their ear canals while burrowing.
It is important to note that the blindness of marsupial moles does not hinder their survival or reproductive success. They have evolved other sensory adaptations to compensate for their lack of eyesight. For example, they have highly sensitive snouts and whiskers that help them navigate and locate prey in their dark underground habitat. These adaptations allow them to effectively hunt and capture insects and other small invertebrates, which make up their primary diet.
The marsupial mole is blind due to the evolutionary adaptations it has undergone to suit its subterranean lifestyle. The reduction of their eyes to vestigial lenses and the absence of external ears are adaptations that have helped them thrive in their unique habitat. While they may lack eyesight, they have developed other sensory adaptations that enable them to navigate and survive successfully underground.