At my dad’s funeral, an auntie I’d not seen for twenty years came up to me and said “Oh my god you’re the absolute spitting image of your dad”

I said, “What, except not dead?” and she burst into tears

Tact was never my thing

There arent a whole lot of pictures of my dad, but hes got a couple where hes a teenager. Everyone confuses it for me, and even I gotta admit I looked a lot like him when we were both around that age.

There is an incredibly, yet none zero chance that all genes passed by one parent may be recessive, while all the other parent’s expressive genes are all dominant and passed on. Theoretically then your scenario is possible.

No. Kids generally tend to be a lot smaller. Once they grow up, yes-ish.

Perfectly identical? I doubt it. Eerily close though, totally. My brother and my dad look so much alike that I’ve mistaken photos of my dad as a kid for photos of ny brother, and my daughter looks like a tiny version of my father-in-law.

As I understand it, the number of DNA combinations is theoretically finite, so yes. Also, your question is limited to phenotype, which wouldn’t require two people’s DNA to be perfectly identical to produce the same physical appearance.

I’m sure someone who knew the genetics involved and was well versed in combinatorics could give you some reasonable bounds on the probability, but the genes that contribute to phenotype aren’t well defined yet. Suffice to say, the probability is very low. Like “number of atoms in the universe” low.

And this is all assuming every strand of DNA in your body is identical to each other, and is YOURS. But mutations happen all the time, and there are cases of finding traces of DNA corresponding to a person’s mother, child, or older siblings in their body, just because they were exchanging blood during pregnancy and those cells can hang around. And you never really know how those cells will propagate or how they’ll affect the person’s development. So in reality it may be much more difficult to compute than in theory.

I might not have the same DNA as her, but I look exactly like my mom did when she was my age. The only thing that looks different is the stature.

Kagi says parthenogenesis hasn’t happened in humans, but that’s the only way I can think of a child being an identical copy of its parent (mother-daughter, specifically).

Which implies Jesus is trans.

Dude there’s evidence of genetically unrelated people looking nearly identical.

My older daughter looked exactly the like her mother at the same age when she was 3-6 years old. When I compare their childhood photos it would be hard to tell which is which, if not for the hideous fashion of the 80’s being a a clear tell for mother.

After the age of 7 my daughter quickly grew into her own look, but when she makes certain faces the resemblance is still striking.

Absolutely identical, no. Even identical twins often have slight differences. Similar enough to cause confusion, definitely.

I was once shown a picture of me on a rock, by the sea. It was obviously me, but I couldn’t for the life of me remember a holiday it fitted. It turned out the picture was of my grandfather. We were apparently similar enough, at least at that age, for me to mistake him for me!

As for the why.

Our various characteristics are controlled by genes. We get 2 copies, 1 from each parent. However, not all genes are created equal. Genes can be dominant or recessive. E.g. brown hair is dominant , while blond hair is recessive. To be blond, you have to have all blond genes. To be brown haired, you only need 1.

Most characteristics are controlled by a number of different genes. However, most have a few dominant controlling genes. If you happen to have a father with a large number of dominant genes, paired with a mother with more recessive genes then you can get a doppelganger for the father. This can become more likely if the 2 parents are loosely related, since the mother is likely to carry a similar set of genes to the father.