Black and White

Holy Shit! Have you guys seen this?

Albino Green Sea Turtle (Chelonia mydas)

GHOSTS ARE REAL! I'm kidding obviously, but seriously how adorable is that? Just when you thought baby turtles couldn't be cuter. But what's the story behind this crazy white turtle? Well first off it's not alone.

Various albino animals.

All of these animals are affected by a congenital condition known as albinism characterized by a reduction or lack of pigment in the skin, hair, scales, etc. as well as pink/blue eyes. Albinism is also found in humans and less commonly in plants where the chlorophyll in the plants is reduced. This negatively affects the plant's ability to photosynthesize which leads to reduced survivability. Albino animals also suffer from their reduced pigment as it can negatively affect their ability to camouflage, or reduce their protection from UV radiation. There have also been studies showing that albino animals have poor eyesight and hearing as well as reduced reproductive viability.

Now while albino animals are strange and eye-catching there is another pigment affecting condition that often gets overlooked. Did you know that these two animals are actually the same species?

Black "Panther" and Jaguar (Panthera onca)

The black panther, as it is commonly called, is actually a title used to describe any of the Panthera species affected by a condition known as melanism.

Top Row: Melanistic and normal jaguar (Panthera onca); Bottom Row: Normal and melanistic leopard (Panthera pardus)

Melanism is the opposite of albinism. While the latter is a condition resulting in the absence of pigment in the skin, hair, etc. the former is a condition which increases the amount of pigment produced. Additionally while albinism has several negative impacts, as described above, melanism is more commonly a beneficial condition. The darker pigmentation can grant greater camouflage capabilities to both predators and prey is many environments, especially at night. Melanism has also been linked to disease resistance in felines; with darker individuals appearing at higher latitudes and in environments where they would be disadvantaged camouflage-wise due to their ability to shake off viruses better than their "normal" coated cousins. Finally there is a wide range of species affected by melanism, from snakes, cats, squirrels, canines, and insects.

Various melanistic animals.

The incidences of this condition in insects are most famously linked to increased pollution from industrial development. For example the peppered moth, Biston betularia, was originally white which camouflaged it against the light colored lichen on the trees. However, with the rise of air pollution in the UK following the industrial revolution the lichen began to die off exposing the dark bark of the trees. This lead to a rise in melanism in the moths as the lighter colored individuals became more obvious to predators.

Peppered moth (Biston betularia) normal and melanistic varieties

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