Is it biologically possible to have two biological dads?

[Anonymous]

Their mom slept with two guys around the same time.

[abc3643]

Believe it or not, I believe it is possible but it would involve an incredibly rare set of circumstances.

Basically, you need to understand what a human chimera is. A chimera is a person who has multiple (often just two) different sets of DNA. Often, each person has his/her own DNA, but some of their mother's DNA may have slipped in while we were busy gestating in her womb.

However, a chimera is a bit different...

Imagine a woman has double ovulated so two eggs are in her womb. When these eggs are fertilized becoming zygotes, they will implant themselves in the uterine wall. If the zygotes are sufficiently far apart within the womb, they will grow into distinct embryos and then distinct fetuses and, at birth, you have fraternal twins - twins with two different sets of DNA.

However, what if those zygotes implant very close to one another? What happens is that, as they grow, the two embryos will merge into a single fetus - a single fetus with two different sets of DNA. At birth, we have one person who should have been fraternal twins but instead is a single person with two different sets of DNA. Such a person is a chimera.

OK, now in both scenarios I described, there usually would just be a single father and both ova would be fertilized after a single round of intercourse. So, the resulting fraternal twins would be genuine siblings sharing the same parents. Same with the chimera.

Ah, but what if the woman - a woman who has double ovulated - has intercourse with multiple men such as in a gang bang or gang rape or orgy or whatever? It is conceivable that one zygote was one ovum that had been fertilized by one man's sperm and the zygote from the other ovum that had been fertilized by a different man's sperm. In this case, the fraternal twins would only be half-siblings - same mother, different fathers. BUT, if those two zygotes which had different fathers then were implanted closely in the womb... You're going to get a chimera... a chimera involving two different sets of DNA still, but from two different fathers and the one mother.

That's how it is possible... And just like you described - their mom slept with two guys around the same time... But, I need to be clear: the child would have to be a chimera; generally, a single ovum cannot be fertilized by multiple sperm cells because the ovum blocks the other sperm once it is fertilized by that first sperm.

That said, I suppose there could failures in that ability to shut down the other sperm. I suspect the resulting zygote fertilized by multiple sperm would not be viable.

[RavVid]

There have been cases where non identical twins have non-identical fathers. But there can't be two fathers of "identical twins".

[DryGermanGuy]

Yes, but rarely. I’d like to bring in an expert:
@AustColombiangirl 😉

[AustColombiangirl]

Funny guy. No

[DryGermanGuy]

For the medically interested, read:

https://en.wikipedia.org/wiki/Superfecundation

[exitseven]

nope, it is an either or situation. Or to the victor go the spoils.

[Mariogirl09]

Only 1 sperms egg meets a female egg

[Ariesman81Nshiiit]

I suppose if the dad had a twin

[Anonymous]

No. Only one is your real dad.

[DirtyOldMan777]

no. that's not who that works

[DirtyOldMan777]

unless the guys are identical twins.

[In_Trance]

Someone missed biology class 15 years ago

[MasterKS]

But the winner will be one, numero uno!

[FrodoSkywalker007]

No...