Research shows not only the fittest survive

University of Exeter ^ | March 27, 2011 | Unknown

[SunkenCiv]

Over 3 billion base pairs; genes are often about 3000 base pairs each, but at least one has 2 million base pairs. OTOH:

http://www.ornl.gov/sci/techresources/Human_Genome/project/info.shtml

Almost all (99.9%) nucleotide bases are exactly the same in all people.
The functions are unknown for over 50% of discovered genes.
Less than 2% of the genome codes for proteins.
Repeated sequences that do not code for proteins (”junk DNA”) make up at least 50% of the human genome.

[allmendream]

Well that is nice that the switching over is not actually likely to change MUCH - because almost all (99.9%) of the nucleotide bases are the same.

But there is still absolutely no reason to go looking for an integer solution to 46/4.

Other than the X and the Y, the chromosomes parents pass down to their children are about a 50/50 mix of grandparental DNA.

[SunkenCiv]

Yes, about 50/50 — one grandparent may have as much as 23 chromosomes passed down, or as little as 0, but on average it’s probably 11 or 12.

[allmendream]

You don't seem to be understanding that chromosomes don't pass down intact. Crossover events ensure that each parental chromosome is a mixture of grand-parental DNA about 50/50. No grandparent has “as little as 0” DNA passed on - they each pass on roughly 25% of the genetic DNA.

That is the reason mitochondrial DNA is interesting, because unlike chromosomal DNA it does pass on intact through the maternal/cytoplasmic line.