Identical twin DNA testing - remarkable results

[IgorStrav]

https://www.cbc.ca/news/technology/dna-ancestry-kits-twins-marketplace-1.4980976

An interesting read and further evidence that ethnicity estimates should be treated with a large handful of salt.

[Mart 'n' Al]

Fascinating and essential for anyone with an interest, but what is meant by "The raw data collected from both sisters' DNA is nearly exactly the same."?

Nearly exactly?

Martin

[KGarrad]

That's a definite maybe, then?!

[Guy Etchells]

All it shows is most individuals who take a DNA test or who write about DNA do not understand DNA.

It might be worth reading-
https://scienceline.ucsb.edu/getkey.php?key=244

https://www.sciencefocus.com/the-human-body/do-identical-twins-have-identical-genes/


Cheers
Guy

[Mowsehowse]

One of the comments below the article:
     Gary Smith says: Twins "start with identical genes, because each is formed from a single fertilised egg that splits into two embryos. But from that moment onwards, their DNA begins diverging. The DNA replication mechanism introduces about one new mutation for every 100 million base pairs copied, per generation.
There are around three billion base pairs in the human genome, so you would expect between 10 and 100 new mutations per person that occur early enough in embryonic development to be present in most cells in the body. Ordinary DNA tests won’t normally detect this because they only examine a short section of the DNA, in a region known to be highly variable between individuals. But if the entire genome were sequenced, these differences would show up."

I have no idea if that is a reasonable hypothesis or not........

[Mart 'n' Al]

Gary Smith's comment sounds reasonable, but everything I've ever read says that identical twins have the same DNA. I could be convinced that GS is right.   It only needs one tiny mutation. I don't understand his comment about 10-100 mutations.

Martin

[melba_schmelba]

Very interesting, the myheritage results seem like an outlier in comparison to 23andme and ancestry. Pity they don't give the LivingDNA percentages.

[josey]

I don't follow his comment about 10-100 mutations.

Could it be a calculation from

The DNA replication mechanism introduces about one new mutation for every 100 million base pairs copied, per generation.
There are around three billion base pairs in the human genome,

I have no idea whether he is talking about human generations or generations of cells.

[Mart 'n' Al]

Yes, reading it again I see. I think he means human 20-25 year generations.

Martin