If twin guys had twin wives and both had children...would the children look identical?

Question

Just always wanted to know!

Answer 1

Interesting question. The intuitive answer may be yes, but the answer is actually

NO.

There are many reasons for this -- not limited to but including:


DNA-based reasons:

The 1st assumption is that twins' DNA are absolutely identical. Because of "jumping genes" that literary reinsert themselves in other places in the genome, their DNA may not be exactly the same after they're born.

The parents may be carrying recessive alleles that may through independant assortment make homozygous recessive kid(s). Say the twin guys are redheads (2 red alleles), and their twin wives are brunettes (e.g. one red & one brown allele). They can have a kid with red hair (a red allele from dad, and a red from mum), or a kid with brown hair (a red allele from dad, and a brown from mum). Brown is dominant over red. Also, females carry 2 X sex chromosomes, and which one is used in what part of her body is random. So a woman with X (colour blind) + X (not colour blind) may actually be either colour blind or have normal vision.

Even though mutations are rare, they do happen. If the guy(s)'s sperm or wife(s)'s eggs carry genetic mutation(s), then you can bet that their kids won't be exactly the same. Mutations are the main reason why older men be more likely to sire a kids with genetic problems (e.g. cri du chat). Very few mutations are needed for a change in the kid -- sickle cell is caused by a single base pair mutation; our next closest primate cousin's DNA is 95% the same as ours. Mutations are also the reason why a perfectly healthy person could develop cancer.

Incomplete disjunction is the reason why women over 35 years are more likely to have a kid with Down syndrome (trisonomy 23).

There is also reciprocal genetic exchange. That is, homologous pairs of chromosomes exchange genetic information before gametes (sperm & eggs) are made. So not all of dad's sperm have exactly the same DNA. This is the major reason why organisms reproduce by having sex at all.


Enviroment-based reasons:

The development of a child in the womb is a very complex process. Slight differences in the environment can make a big change in the kid.
E.g. one mother may have drank a lot of beer (ethanol is a teratogen) while pregnant. She would have a retarded kid, while her sister may not.
E.g. not even twins' fingerprints are exactly the same.

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Answer 2

If a man and women had 4 children would they all look the same?
Same gene pool...same chance to all look identical. Doesn't often happen, does it? So how much chance do you think the kids of other parents have, even if the parents were identical twins paired with other identical twins? Not likely, but I do think they would resemble each other like normal siblings often do.

Answer 3

The chances hover around zero.

Fraternal twins result from two ovulations (Dizygotic); identical twins result from one split embryo (Monozygotic).

Identical twins do not run in families. Fraternal twins must be on the mother's side to have an effect on the outcome.

The miniscule odds factor in the genetic recombining involved. Exact duplication is virtually impossible.

The statistics for twins say Identicals occur 4 times in every 1000 births; fraternals, on the other hand, average 12 in every 1000 births.

Answer 4

If both sets of twins were identical twins, and they each had a set of identical twins, it is possible that the second-generation twins could have very similar characteristics, simply because the split at the time of the twin parents' conception would have given each twin from generation #1 the same gene set.
Fraternal twins are different, usually one male and one female. My grandfather had a twin sister, and although they had similar features (height, weight, and facial features), they were totally different on the personality scale. I would guess that it depends on how strong the dominant gene is on each side of the families the twin parents came from.
Twins are rare, and a second-generation twin set from both twin parents would be even more rare, good question, though.

Answer 5

LOL - could they be same cousins? No, the nutrition and studies of the mummy in the time of being pregnant, to boot as unexpressed genes could play a function in coming up changes between them.

Answer 6

No. You would still have 4 different sets of genes to deal with. I have 4 children, while they favor one another they are by no mean identical.

Answer 7

unless the twins had twins themselves then it would look identical, not one egg is the same as the other along with sperm they are are different they just share similar characteristics (that is how you can tell some people are related) but unless that egg splits and makes two identical halves (children) then they wont be identical looking children

Answer 8

No.
You still have 4 sets of genes even if they are twins.
And each birth is a separate rolling of the genetic dice.

Answer 9

Unlikely.

Answer 10

Probably not. But twins are more likely to have twins!

Answer 11

Family often favor, anyway. Are these twins identical?