A white lion cub, a very rare color morph, has been causing quite a stir amongst visitors a Kruger National Park in the Republic of South Africa (mostly because he's so darn cute). This little rarity is a member of the Satara Pride and is one of only 13 wild white lions. White lions are so rare that none were seen in the wild from the early 1990's until 2006. And since 2006, only 16 white lions have been born and in only 5 lion prides, all in the Kruger/Timbavati region.
Why are they so rare?
White lions are a result of leucism, or lack of pigment which results in light coat and eyes. In lions, leucism is caused by getting a copy of a gene which has a recessive mutation from both mom and dad. For two tawny lions (the typical brown/tan color) to have a white lion cub, both lions would have to be carriers of the recessive allele, meaning they have the recessive copy but they display the dominant one.
It is quite possible that the statistics are way more complicated and that there may even be more than one way to be 'white.' It has been speculated that light coat in white lions with yellow eyes may we caused by a different gene than in white lions with blue eyes (the TYR gene versus a gene similar to what creates white cats and white tigers). Genomic analysis of big cats is just beginning but don't you worry, we're getting to the bottom of it!
I am a biologist and my life is crap!