Identical twin girls marry identical twin boys and each have a kid. Will their children be identical as well?

Question

Just wondering this as I was watching an old doublemint commercial. How close would the children's DNA be, and how identical would the children be in other ways?

Answer 1

This question is really similar to another one I have answered, here is some cut and paste goodness.

I think they would certainly look more similar than normal cousins, but they would not be the same by any means. Each parent has two copies of each chromosome that are not identical to each other. Mixing and matching between these would lead to four possible combinations;

Father: AB Mother: CD Children: AC, AD, BC, BD

4 possible combination for each of the 23 chromosomes would lead to 92 combinations for each child. That would lead to about .01% chance of them being the same if that was the only factor in genetic diversity (which it is not).

In humans, the two chromosome copies also cross over and exchange information during meiosis. Crossing over is a random event that is largely unpredictable and would cause these hypothetical cousins to be no more related than a normal brothers/sisters.

Answer 2

There is a phenomena in humans & some other animals called crossing over ; this occurs in the production of DNA for reproductive cells (sperm or egg) to increase the combinations of ways the existing genes can be arranged & therefor expressed. What all this means is that even with alot of shared DNA, the kids will not automatically be as alike as it might sound. But regardless, with humans, you cannot tell for sure, because the genetics cannot predetermine a mind; only tendencies.

;-)

Answer 3

Not necessarily. This is because there are recessive genes in each partner. Thus, there are practically an infinite number of combinations that must occur before an identical child is born from different parents.

Answer 4

No but it is very likely that they will be genetically simular.

Or put it this way. If your parents have another kid, will that kid be like you? Generally the answer is somewhat, yes.

Identical Twins have simular genes so you'd think that the "cousins" would be ALMOST like siblings.

(In fact even identical twins have differences. Usually one can tell them apart which means there are differences in their genes somewhere.)

Answer 5

The children will have no more chance of being identical to a cousin than they would to a sibling. Actually, double first cousins, whose parents are identicals married to identicals, are - genetically - siblings.

Answer 6

its more likely to be no... because even the pair is like identical, the combination or the traits that will be inherted may be diiferent, for example a trait of the skin for the child in the 1st pair will be from the father, and for the second 2nd pair the trait will be from the mother... so there is a larger possibility that it will be no, but still there is a small possibility that they may have identical child.

Answer 7

genes are kind of like a rulete game sometimes. I.e. two parents have brown eyes but kids have blue eyes. What are the chances of that? But i agree with most of the others, that they will probably appear similar, but will show differences, especially later in life just as twins show differences in time.

Answer 8

Depends on which genes are dominant and which are recessive. Gene expression is uncertain without knowledge of the parents' alleles and even then there are different combinations that could occur.

Answer 9

This actually happened. The children were genetically siblings rather than cousins. I don't recall that any of the children were twins.

Answer 10

8ts possible dat their children will be identical too because of their genes.