3 ms·

I guess it might also be possible, then, for semi-identical twins to have different fathers?

• aTrillion 8y ago
  Probably many a trillion times less likely. Already, in the history of genetic testing we’ve noticed two among billions, even with retrospective testing of ancient DNA. While we haven’t tested all living humans, we certainly know the typical rate of fraternal twins, so, with that as a benchmark for how infrequent twins usually are, over millions of years, this happens even less. Even with lawlessness, relaxed social norms and the simultaneous sharing of sexual partners throughout history. Even with evolutionary ancestors like higher primates.
  • jobigoud 8y ago
    But it could be done in vitro maybe.
• clairity 8y ago
  this happens all the time in other animals. i'd adopted two cats (boy and girl) who were littermates but had different fathers. their coat patterning and eye color were different even though their coloring and (small) size were similar.
  • scarmig 8y ago
    That's fraternal twins, though, not identical.
  • cimmanom 8y ago
    Animals that commonly produce liters of multiple offspring typically do so by releasing multiple eggs simultaneously in each period of fertility. This also happens in humans in the case of fraternal twins (two eggs each fertilized by a different sperm). That’s very different from one egg being fertilized by a single sperm and then splitting (which produces identical twins) or being fertilized by two sperm (which is what happened in this case).
    • clairity 8y ago
      right, that was a bad example (multiple eggs with multiple sperm from different fathers, not single egg with multiple sperm). i can't remember where, but i do remember reading about this happening in other animals.
• deleted 8y ago
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