I saw this recently – Identical twins aren’t all identical, study finds – Atlanta Journal-Constitution January 11, 2021: https://www.ajc.com/life/identical-twins-arent-all-identical-study-finds/HOSADOGW6RHIDL5UXSTMX3O6LE/. It’s a longer article, but here’s enough to give you some basic information. Decided this was a good Weirdness Wednesdays post. This is a point often missed or ignored by DNA experts. I saw a TV crime show where one identical had committed a murder. In the episode, they were able to figure out which identical it was by looking at the minor differences between the identical twins. Once I saw the episode, I checked it out and turns out the TV show got it correct. The differences can start in the womb. While identical twins share the vast majority of DNA in common, there are minor differences that range from being in the womb to after birth. For basic genealogy DNA tests, the odds of seeing differences between identical twins are very unlikely as the companies only test a small fraction of DNA.
By Nancy Clanton, The Atlanta Journal-Constitution January 11, 2021
Do you have an identical twin? Are you sure?
New research finds not all identical twins have identical DNA, and the differences can begin early in embryonic development.
Identical, or monozygotic, twins come from one fertilized egg that splits in two. The pairs have been important in scientific research because physical and behavioral differences were presumed to be caused by the environment, the Guardian reported.
“So if you take identical twins raised apart and one of them developed autism, the classic interpretation has been that that is caused by the environment,” said Kari Stefansson, a co-author of the paper.
Other Weirdness Wednesdays posts: https://upsdownsfamilyhistory.wordpress.com/tag/Weirdness-Wednesdays/