This is typical to examples seen elsewhere in nature, where male mules are pretty much always infertile, however hinnys (female mules) are occasionally fertile i.e. a male with a strange number of chromosomes is less likely to be fertile than a female with a strange number.

I think there is a similar situation with the Liger/Tigon hybrids, one is supposedly more fertile although I can't remember which. Genetics is definitely fascinating.

 

It would be interesting to see a study that did investigate the father's age and effect on nondisjunction rates, for comparative data on the effect of aging mothers...and I agree, the stats on those DS women that indicate incest are definitely disturbing, my mother works at a sexual assault crisis center and the number of cases she sees as a result of mentally disabled people being taken advantage of is really disheartening...

Many people born with Downs can have a productive life. Some are very loving people.

Many people born with Downs can have a productive life. Some are very loving people.

I totally agree, I have a friend whose mother really struggled on deciding whether or not to continue a pregnancy after the amniocentesis showed it was a Down's baby, and she did decide to keep the baby, and now they are so incredibly glad. He is one of the most inspiring people I've ever met, you can't help but love him.

I totally agree, I have a friend whose mother really struggled on deciding whether or not to continue a pregnancy after the amniocentesis showed it was a Down's baby, and she did decide to keep the baby, and now they are so incredibly glad. He is one of the most inspiring people I've ever met, you can't help but love him.

Downe's Syndrome (that's what it's called' date=' Down Syndrome is what it is often wrongfully called, often even by doctors who don't specialise in Downe's Syndrome)

The mutation of the 26th chromosome (completely off the top of my head so I might have the number wrong) that causes this disorder has, interestingly enough, been linked to evolution. I read it earlier this year in the 2003 Comprehensive Oxford Science Journal, though can't remember the exact explanation. You might want to look it up.

I know inbreeding often causes people to have similar disorders to this but not sure if it actually affects the rate of actual Downe's Syndrome. I could be wrong though.[/quote']

 

The correct name is Down or Down's syndrome. It was named after John Langdon Haydon Down, an British physician in the mid 19th century. Please see the following link for his biography:

 

http://www.whonamedit.com/doctor.cfm/335.html