Albinism.
Albino animals are one of the most rare in all defects of animals. Albinism is caused by the absence of melanin in the pigment of the skin. Most animals can no longer camouflage to survive, therefore the rate of wild albino animals are low. Eyes of albino animals usually appear red because the colour of the red blood cells in the retina that are visible because there is no pigment to cover it. Melanism is the direct opposite of Albinism which usually makes the pigment darker than usual because of the excessive melanin.
There are two forms of albinism. One is lack of melanin and is known as hypomelanism or hypomelanosis. The other being no melanin at all, known as amelanism or amelanosis.
Most forms of albinism are the product of the genes passed down from both parents of an animal, but sometimes rare forms occur from only one parent. There are some other mutations which are proven to be linked with albinism. But all others lead to decreases in melanin production in the body.
The chance of a animal with albinism from the only one parent with albinism is rare. However, because some organisms can cary genes for albinism without showing any signs, albinistic animals can be produced by two animals without Albinism. Albinism mostly occurs with the same rate in both female and male. One exception to this is ocular albinism, which it is passed on to an animal through Y chromosomes. So, ocular albinism happens more often in males as they have one X and one Y chromosome. But females, who have two X chromosomes.
[edit]
Most forms of albinism are the product of the genes passed down from both parents of an animal, but sometimes rare forms occur from only one parent. There are some other mutations which are proven to be linked with albinism. But all others lead to decreases in melanin production in the body.
The chance of a animal with albinism from the only one parent with albinism is rare. However, because some organisms can cary genes for albinism without showing any signs, albinistic animals can be produced by two animals without Albinism. Albinism mostly occurs with the same rate in both female and male. One exception to this is ocular albinism, which it is passed on to an animal through Y chromosomes. So, ocular albinism happens more often in males as they have one X and one Y chromosome. But females, who have two X chromosomes.
[edit]
Melanism
Melanism is an development of dark-colored pigment in skin and is the opposite of albinism. The word ‘melanism’ comes from a greek word which means black pigment. Pseudo-melanism or abundism, is another form of this, recognized by black spots or bigger stripes, which usually cover a large part of the body of the animal making it appear black.
Melanism animals are usually very adaptive according to there color. Usually, darker animals get in better shape to survive and reproduce in an environment where they are better camouflaged. This makes some animals less visible to predators, but others like a black panther, use it as an advantage during night hunting. Usually adaptive melanism is genetic. A powerful gene, which is almost entirely shown in their genes behaviour is responsible for the overly enormous amount of melanin. Adaptive melanism has shown to happen in a bunch of animals, including mammals such as squirrels, many big cats and canines, also coral snakes.
Melanism animals are usually very adaptive according to there color. Usually, darker animals get in better shape to survive and reproduce in an environment where they are better camouflaged. This makes some animals less visible to predators, but others like a black panther, use it as an advantage during night hunting. Usually adaptive melanism is genetic. A powerful gene, which is almost entirely shown in their genes behaviour is responsible for the overly enormous amount of melanin. Adaptive melanism has shown to happen in a bunch of animals, including mammals such as squirrels, many big cats and canines, also coral snakes.
|
|