Naked Science Forum

General Science => General Science => Topic started by: rex on 20/08/2007 11:57:00

Title: brown eyes
Post by: rex on 20/08/2007 11:57:00

hi can you tell me how my daughter has brown eyes i have blue my wife has blue her mum and dad have blue my dad has blue my mum has brown?

Title: brown eyes
Post by: chris on 20/08/2007 14:10:13

Hi Rex

welcome to the forum, great to have you with us.

The simple answer is that several genes are involved in the metabolic pathway that leads to iris pigmentation; in other words brown eyes.

These genes form a sequential metabolic pathway where the product of one part of the pathway feeds into the next part of the pathway. So nn interruption caused by a non-functional gene at any point in this pathway can produce blue eyes.

Hence you may carry genetic changes that interrupt the pigment-pathway in one place, giving you blue eyes, but your wife carries a genetic change at a different point along the pathway.

But when you mix up your genes with your wife's then the two "broken links" can be fixed by a functional copy of the gene from the other partner. So the pathway resumes pigment production in your daughter. Hey presto, brown eyes!

There is of course another explanation, but you probably don't want to consider that!

Chris

Title: brown eyes
Post by: neilep on 20/08/2007 14:15:17

Hi Rex, welcome also !

In addition the above good doctors excellent post you might just want to point your mouse at this link as this subject was only discussed very recently here on the site



http://www.thenakedscientists.com/forum/index.php?topic=9427.0

Title: brown eyes
Post by: Karen W. on 20/08/2007 14:17:59

Good Job I could not find it!LOL Thanks Neily!