I think i'm right in saying that it would be perfectly legal for two male twins to get married to one of a pair of female twins.
Now if they are both identical piars, would it be possible for there children to look very very similar? I'm doing about genes in biology (gcse but we're doing quite a bit of a level stuff) and i know that basically parent genes get split up so there is one chromosome from each parent then the genes go to the embryo and get jumbled around and that why some aspects of people look like there mum / dad more than the other. So is it possible that the genes get jumbled around in almost the same way, creating two cousins which look almost identical?
Yes legally but with 6+bilion of us on the planet its probably not going to affect the gene pool.
I do know a pair of twins who married to sisters who looked very similar. They had a "Stepford wives" look about them as a group but they all semed pretty happy.
Isn't that assuming that all the children from a set of parents will look very similar? My 3 children all look entirely different, we've got straight blonde hair, dark curly hair and straight darkish hair. Also brown eyes, blue eyes and grey eyes - with all this variation going on between 2 gene donors (if you like) there seems to me to be a large amount of variation in the possible appearance of twin cousins.
I hasten to say that my children all have the same father! lol!
With both sets of parents being identical twins, the children from one set will genetically have the same chance looking like the ones from the other set as the siblings from any parents have. They are in fact genetic siblings. This would be quite different if the twin parents were not identical.