Population genetics

Face of the day

Inbred White Tiger Kenny

Inbred White Tiger Kenny

Today’s face of the day is going to blow your mind. Well it blew my mind anyway. Miss Whaleoil told me about a White tiger with Down’s Syndrome and I thought surely not. I found one article that claimed he had Down’s Syndrome and then another more scientific one that had another explanation. He apparently died in 2008.

Kenny is a white tiger that was ?selectively? inbred while in captivity in the United States. As zoos and exotic pet stores along with consumers have increased the demand for white tigers, breeders have attempted to recreate the ideal white tiger ? large snout, blue eyes, white fur ? by relying on a limited pool of white tigers that are in captivity.

The result? With such a limited gene pool, white tigers are born with an astoundingly high rate of deformities and health issues. For example, Kenny is mentally retarded, has significant physical limitations, and is considered the first tiger with down syndrome. The pictures, in many ways, speak to the condition that Kenny and other white tigers are in.

–pbh2.com

Read more »

What happens when cousins marry and breed?

In New Zealand we have laws that prevent same sex marriage, yet allow first cousins to marry. What are the odds of genetic mutation from first cousins marrying:

The inbreeding is computed as a percentage of chances for two alleles to be?identical by descent. This percentage is called “inbreeding coefficient“.

Ironically the inbreeding?coefficient?for first cousins is 6.25% which is probably the same percentage as there are homosexuals in society.

What are the issues of inbreeding then?

A 1998 review found 1-4% increased?morbidity?for offsprings of first cousins compared to offsprings of unrelated parents. A 1994 review found 4.4% increased?mortality?for offspring of first cousins. After controlling for several sociodemographic factors, infant mortality for offspring of first cousins had?odds ratios?of 1.36, 1.28, and 1.32 for the neonatal, postneonatal, and infant period. There has been little research on how inbreeding affects common adult disorder although some preliminary evidence support effects on many such disorders including cardiovascular diseases and common cancers. Many previously not identified genetic disorders have first been recognized in highly?endogamous?communities and the mutation causing the disease may be unique to such communities.

A review of 48 studies of children born to cousins found that most of the children were healthy, with birth defects affecting 4% of births for consanguineous couples compared to 2% for the general population.

So we have laws that allow first cousins to marry and as a result have an increased risk of genetic deformities and illness. None of this happens with sam sex marriage and yet that is prevented by law?

Enhanced by Zemanta