Inheritance of DNA

[JMB1943]

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

[Gadget]

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

[Biggles50]

Google

DNA Recombination

[pughcd]

@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.

[Gadget]

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%)


Gadget