If Adrien and Marinette had children, what eye color would they have?

(Graphic made by @azurajae. Click to enlarge.)

It’s time for mlscience’s first actual post! This topic is actually the thing that started it all. A few days ago in the mlsubbing chat, we stumbled upon the topic about what color Marinette and Adrien’s children would be. The result is the above graphic.

Using the beauty of the basics of Mendelian inheritance and Punnett squares, we concluded that if Marinette and Adrien were to have a child, there’s a 50% chance of it having green eyes and another 50% chance of getting blue.

(Click “Keep Reading” for the full explanation.)

After googling a bit, we found that for eye color, green is dominant over blue, and brown is dominant over green. The Punnett squares are based on this assumption. We’ll be labeling the blue gene as “b”, green as “G”, and brown/black as “D”.

Before finding out what eye color your children would have, you would need to find out what eye color your parents (and grandparents) have. This would indicate what genes they have that could be passed down to your children.

For Marinette, finding out her parents’ genes was easy; we can see both her parents in the show and we can also see that they both have brown eyes.

Since Marinette has blue eyes, we can deduce that both Tom and Sabine have the blue gene along with their more dominant brown gene. This also means that Marinette is the 25% chance that Tom and Sabine get a child with blue eyes:

EDIT: Since a lot of people have been saying that Tom and Sabine’s eyes may not be brown (green and gray, respectively), we made some more Punnett squares that would show all possible combinations here.

For Adrien’s genes, it’s a bit trickier since we have never seen his mom’s eyes, but we can look at his dad, Gabriel, and see that he has blue eyes:

This means that Gabriel Agreste has both recessive blue genes. Since Adrien has green eyes, that means that his mother must also have the green gene that dominates Gabriel’s blue. We wouldn’t be sure about her other gene, but since Adrien already has green eyes and given that Gabriel has blue eyes, we can confirm that Adrien has one dominant green gene and one recessive blue, and that his mom’s other unknown gene isn’t necessary. Adrien is the 50-100% chance that Gabriel’s partner would give birth to a green-eyed child:

Now that we know that Adrien has Gb and Marinette has bb, we can now cross these genes to find out their children’s potential eye colors:

CONCLUSION: 50% chance of blue eyes, 50% chance of green.

Also, we can expect that Adrien’s mom would have green or dark eyes, if the makers of Miraculous Ladybug took genetics into account.

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UPDATE (3/11/2016): ‘Jackady’ has proven our hypothesis that Adrien’s mom would have Green or Dark eyes!

In this case, a lovely green:

These green eyes lead us to conclude that she could have only two possible genotypes: GG or Gb. GD is impossible because that would require her to have black/brown eyes, which she doesn’t have.

Here’s a couple of Agreste eye color Punnett squares:

If Adrien’s mom had GG:

(If this is the case, any siblings that Adrien has/could have would have Green eyes.)

If Adrien’s mom had Gb:

(If this is the case, Gabriel and his wife have a 50% chance of producing blue-eyed offspring. This Punnett square is identical to Adrien and Marinette’s Punnett square.)

Do note that none of these amendments affect the possible genotypes for Adrien and Marinette’s children.