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General => Ancestral Family Tree DNA Testing => Topic started by: JMB1943 on Tuesday 08 August 23 19:01 BST (UK)
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We know that we inherit our DNA from our parents.
It’s almost automatic to think 50% mother & 50% father.
However, it is known that it is never exactly 50:50.
Has it ever been determined what the extreme values are? 60/40, 70/30/, 80/20, 95/5?
Or even an average value, if such a thing exists?
Regards,
JMB
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Painter gives average for each parent as 3485 with a range of 2376 to 3720
https://dnapainter.com/tools/sharedcmv4
Gadget
Add - also this is worth reading
https://isogg.org/wiki/Autosomal_DNA_statistics
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Google
DNA Recombination
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@JMB1943
The widely accepted rule is that we all inherit 50% of our DNA from each parent.
However, some people argue that whilst the autosomes are generally the same size, the X and Y chromosomes are not equal in size so theoretically males (XY) inherit slightly less DNA than females (XX). The Y-chromosome is one third of the size of the X-chromosome and contains about 55 genes while the X-chromosome contains about 900 genes.
https://www.genome.gov/about-genomics/fact-sheets/Chromosomes-Fact-Sheet
When you take an autosomal DNA test like Ancestry DNA , 23andMe, Ft-DNA you may be getting some X and Y chromosome analysis but as far as I am aware only FT-DNA reports the X-chromosome data in the results.
https://isogg.org/wiki/X-chromosome_testing and https://isogg.org/wiki/Autosomal_DNA_testing_comparison_chart
It is never 60:40, 70:30 or 80:20.
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Here are the shared cMs with close relatives who have taken an Ancestry test that I have access to. It may be of interest (or not!)
Me
A With niece - 1846 (26%)
B Her son -1100 (16%)
C Her daughter - 836 (12%)
D With 1st cousin (paternal) - 603 (9%)
Niece
B With son - 3450 (50%)
C With daughter - 3478 (50%)
D With 1C1R - 278 (4%)
Siblings
B - C 2531 cM (42-52%)
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