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White Lions
Despite the widespread among amateurs opinion, white lions - not albinos. They simply have a color. As in humans - have brunettes and redheads have, and there are blondes, which is becoming less and less. That white lions is getting smaller - by far the world has no more than three hundred individuals.
White lions are not albino, they are the result of a recessive gene action that stops the body's production of melanin. Recessive gene - a gene whose presence is necessary for the pairs in the "normal operation" of the body. Features of each animal (and, by the way, man!) Are defined by pairs of genes. One of the genes for each of the features you get from the mother and one - from his father. Together, these genes determine whether you have blue eyes, your father, or brown - the mother. So what makes a recessive gene? He does something that is not in favor of the lions. It makes the skin cells lose the ability to partially lion produce melanin.
Melanin - this is what your body uses to make the skin and dark hair. By itself, it's black, but under the influence of the compounds controlled by other genes, it can take any color, even bright red (ask any red). Melanin may also receive the same yellow-brown color, which have lions. Because the cells of different parts of the body partially cease to allocate melanin, lions may take any color - from creamy beige to a snow-white. Some have white coloring of some parts of the body, and cream - other; others are painted flat white and cream color. Sometimes the selection of melanin is also violated in the eyes. This can give the lion pale blue eyes, so often found in white tigers. But at the same time, the white lions may have amber eyes of ordinary lions.
White lions are very rare. Very few lions are white / brown genetic match. This lion (lion called heterozygous) to produce white lions must mate with a lioness, which also has a white / brown genetic match. Both of them can pass either "white" or "brown" gene; Thus, the chances of a white lion cubs from such a union can be roughly estimated as one in four.
In short, they are rare because:
• very few lions have a gene "white" color,
• need a meeting of two of these lions and
• even if they are met, the chances of getting the white lion cub from their union represent only one in four.
Scientists believe that the "white gene" lions left from ancestors who lived in the Ice Age, when the white coat color was needed for camouflage.