Do identical twins have identical DNA?
?? I would think so but….?
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Yes. One embryo splits into two. Both have the exact same DNA. There can still be some outward differences, because of environmental influences. Sometimes they are mirror image twins.
I know how twins occur but the environmental effect is very Interesting.
@Rarebear Interesting. I wonder how often the twins differ at birth? The article suggests the genetic differences increase with age, which makes sense to me.
I can’t Google this up, so I can’t provide a link. But maybe someone here heard the same story and can link to it.
On the radio (local NPR station) recently I heard a story about parents who had identical twins.
Before the birth, they were told one of their sons would be stillborn. But the sick baby lived for a little while. They got to hold him. But he never made it out of the hospital. Heartbreaking. I can’t imagine how much that hurts.
They donated their son for science. And years later they traveled around the country to meet the people who studied and learned from his remains. It’s a beautiful story about science and death and making the most our time on Earth.
But on topic – part of the research was comparing the surviving boy’s DNA to his brother’s. Why did one make it and one not? And the number that sticks in my memory is they found 1,000 differences.
Anyway, long story short – does anyone else remember the recent public radio story about the parents’ quest to follow their little boy’s influence on medical research?
Nope.
I had a couple of friends in high school who were identical twins. James and Jason. They looked completely the same, except Jason had a massive port-wine stain over half of his face. James had no birthmark at all.
They’re close, but not exact.
They may start identical, but every time a cell divides, there’s a chance that an error will be made on DNA replication. (That’s how cancer sets in, by the way.) So, after a while the twins will no longer have 100% identical DNA.
The DNA is different enough to be two individuals, but close enough that they often cannot be differentiated for criminal prosecution. There are cases of one twin committing a crime, but both showing up and no one can figure out which one did it so they both go free,
@Seek Birthmarks are usually not of genetic origin.
@Dutchess_III et al. It seems they do not have identical DNA. My bad.
i think that may be immoral.
@Dutchess_III It’s only immoral if you are in a repressive cult. Most people consider it something healthy.
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