Eye colour

[Fireants]

Mum 1, Dad 1 and son 1 have brown eyes. Son 2 at 6 months has piercing blue eyes.

Mum’s mum has blue eyes and all her siblings and parents have blue eyes.

Please explain why Son 2 has blue eyes to calm Dad 1 down.

Simple genetics. I have brown eyes, my brother has blue.

It's a recessive gene so likely to come via grandparents rather than parents. Is he doubting dc2 paternity?

Because Genes are a wonderful thing and like to throw a blue eyed kid in the mix.
We have a brown eye kid, Dad blue, Mum bluey, son 1 sparkly blue, son 2 is brown, as is his Grandma.

All Mum’s sisters have brown eyes and her dad has brown eyes.

If both of you have brown eyes, then there is generally a 25% chance that the baby will have blue eyes if both of you carry the recessive blue-eye gene.

As above but hopefully she has real life support when her partner needs to “calm down” rather than Google eye colour genetics.

Brown eyed parents like the mother in this scenario, can by hybrid (1x dark (dominant) and 1x blue/grey (recessive) gene (which has to be there as one parent is blue eyed, therefore has 2x recessive blue/grey

Father is probably hybrid too - it just takes one blue-eyed person in the family tree (even if it's many generations ago) to get that recessive gene there. And it's a 1/4 chance that 2 x hybrid brown eyed parents produce a blue eyed child.

Plus, if the brown gene is for some reason not properly expressed, that can also lead to a blue-eyed child

Blue eyes are recessive. You could have generations of brown and then a blue shows up.

The other way round you'd have some 'splaining to do.

Historically blue as been the recessive eye colour in the UK so you can carry a blue eyed gene and a brown eyed gene but would have brown eyes because the brown gene dominates the blue gene. However, if Mum and Dad both pass the recessive blue gene to their child, the DC will have blue eyes.

It used to often be said that two brown eyed parents can have a blue eyed child but two blue eyed parents can't have a brown eyed child but I don't think this holds true, especially as blue is becoming more commonplace.

But if dad needs calming down you've got bigger issues.

Thank you. Mum 1 stood and talked to her blue eyed grandparents saying that it’s weird her son has got blue eyes.

But if dad needs calming down you've got bigger issues

This, a thousand times over.

I have blue eyes (as do both of my parents) my husband has brown eyes (his mum has blue his Dad has green)
Our two children have Green eyes ! Genetics work in their own way!
Both children had piercing blue eyes till around 2 when they eventually turned Green.

I think my dad thought my mum had some explaining to do as everyone in my family has blue eyes, both my parents and 3 siblings. But here I am with green. I've been called the milkmans child my whole life.

I'm pretty sure I do belong to my dad though 😊. It's genetics OP. These curveballs get thrown out like this at times.

What about green and blue ? My parents have green eyes and blue and mine are blue/grey yet I thought green was dominant over blue

I agree, eye colour sounds the minor issue here !

@MrsTerryPratchett

But if dad needs calming down you've got bigger issues.

Someone needs a word with the dad.

Is the mum ok?

@elsaesmeralda

What about green and blue ? My parents have green eyes and blue and mine are blue/grey yet I thought green was dominant over blue

I agree, eye colour sounds the minor issue here !

Sounds similar to my dd. Her dad has blue, mine are green and hers are a mix of blue/green with brown specks thrown in to confuse matters. My ds had crystal clear blue. I do find genetics really interesting though.

Dad is fine but genuinely can’t understand that after a family of brown eyed people and married to a brown eyed wife, with brown eyed sisters and father- his son has blue eyes.

I have brown eyes, my Dad had brown eyes, my mother had blue eyes. The father of my children has blue eyes, I have 2 children, one has blue eyes and one has brown eyes. Does it really matter?

DS2 still had piecing blue eyes (like his granddad) at 6 months. His eyes are now hazel. Eyes change. My brothers didn't settle till he was hitting puberty IIRC.

Did Dad never do punnett squares at school?!

I have green eyes, DP has brown. DD was born with black eyes, which went navy, then progressively lighter blue, into green, hazel, and now brown. She's 4. At 6m she definitely had blue eyes.

Punnett Square.

Brown is dominant, so parents with brown eyes can have a blue gene and a brown gene each. Their child gets one gene from each parent so two blue genes can combine and you get a blue eyed child.

Both of our boys have brown eyes and both of our girls have blue eyes. We both have blue eyes.

Just means dad also has the regressive gene. I have brown eyes, all 3 of my kids have blue eyes, their dad has blue eyes. If I partnered with someone with a recessive gene instead, we would have had 50% chance of having blue eyed children, rather than the 75% chance.
My brown eyed gene has now gone from my descendants. I'm way too old for any more kids

My mum has brown eyes, me and my sister have brown, my brother had blue. My mum has the regressive gene from her dad as he had blue eyes. The gene can stay hidden by a dominant brown ( or green ) eye gene for generations.

You need the gene to be passed on by both parents for it to show in the eye colour.

genetics.thetech.org/ask/ask59

This explains it well, including green eyes too. Basically Brown dominates Green and Blue ( you can carry both green or blue and pass them on and still have brown eyes)

Green gene will dominate Blue, you have to have both parents pass on a blue gene for the colour to show. The green colour will show if no brown gene to hide it and will hide a blue gene if you have one of each.

There are a few other genes for other colours. But this is what happens with Brown, Green or Blue.

Pretty cool hey!

We both have brown eyes I mean!