BOB said “The recessive gene will still be there and still find it’s partner occassionaly but this will happen less and less often”
Not so because the recessive gene does not disappear.
The recessive gene is not expressed but stays in the genome and has the same probability of being passed onto the next generation. Overall, the chances of getting a pair a “blue” genes remains identical.
Evolution is achieved through selection.
For instance, if blue eye people were less likely to reproduce for whatever reason, they would indeed progressively disappear, even though it would take a very long time.
Any stats about fertility rates?
My brother is biracial (white father with brown eyes and my mother who also, obviously has brown eyes). His wife has red hair and blue eyes. They have a little girl who has blue eyes and red hair. Let’s call my brother T and his wife G.
T-----G
Bb----bb
BB----bb
Their chances of having a blue-eyed child, provided my brother’s father had the gene for blue eyes (or perhaps two, but I think he’s got brown eyes himself) was 25%. They just had a boy in November. I’m not sure what color his eyes are yet…I will let you know if Mendel was right or not as far as my family is concerned.
Speakpigeon - The chances of the recessive gene finding their pair are not going to be identical if new breeding partners, of whom none possess the gene, are continualy being added to the gene pool. Or am I still missing something here?
I imagine there will come a time however when “apparently” asian (for example) people start having the odd blond haired, blue eyed baby. Won’t that be a suprise!
BOB, if you add people with a different DNA make-up then the proportion of blue genes will diminish, not their number.
But you are right, if people intermarry, because blue is recessive, the number of blue-eye people will diminish as you keep adding people with brown-eye DNA.
Now, they won’t disappear completely. Many brown-eye people have blue-eye DNA and they will keep producing blue-eye babies. If you stop adding brown-eye DNA people, the proportion of blue eyes will regain its stability.
And aren’t blue-eye people more easily sperm-donors?