Saturday, March 08, 2008

Heteropaternal Chimeras?

I've been dipping into the topic of people with 2 sets of DNA, who are technically known as chimeras.

Basically, a couple of fraternal twins merge in the womb, into a single person.

Sometimes fraternal twins have 2 different fathers, by a process known as heteropaternal superfecundation.

So, given that fraternal twins can merge, and also given that fraternal twins can have 2 fathers, the possibility is raised that one person could have 2 fathers.

Maybe in practice it wouldn't be feasible. But inquiring minds want to know!

Has anyone ever had
More than one dad?


Shiwa said...

Hi John and Mascot!

It is logically possible to have a bipaternal chimera, as long as the heteropaternal twin zygotes become a single zygote within about four days; superfecundation lasting up to five to seven days depending on the length of menstrual cycle.

I’m almost certainly a chimera myself, there being much evidence for it including some mendelian genetics that don‘t match what is expressing (eg, i have dry earwax when it is supposedly wet). Whether i’m also a bipaternal chimera it may be impossible for me to prove; however i found your post in trying to find anything out on this as i suspect that i could be. It would explain some strange things about me!

Should i be chimeric bipaternally
How must i to put in genealogy?

John E. said...

Wow. Interesting. And I hadn't even thought about the problem of how to draw a proper family tree!

Anonymous said...

It certainly is interesting! Difficult for folks to get their heads around this, could cause all sorts of ”existential” problems!

Found this:
To quote:

”Theoretically then we could have someone with chimerism who has two different dads. Basically the first step would be that two eggs get fertilized by different men’s sperm. Then these twins would fuse together to create a chimera with two different dads.

”Since both steps are rare, it will be really rare for both to happen at the same time. But it is definitely possible.”

Just found this, although it is thought by some that chimeras are more common than thought.

My interest in this is because a DNA-test gets it correct about my mother’s ancestry, but the rest not like my mother’s and matching nothing at all of what i look like —being Indianish in the Romany sense (i have almost doubles in Hungary)— which is also unusual for where i was born—the problem being in that i have only a suspect for my father who indeed does look like me, and a Rom from Hungary. Thus, i began to wonder if one could have two different fathers and that the tested DNA is from the other…and, like you, i have an inquiring mind. :)

Shiwa said...

Didn‘t get name in!