mountainlion:
"I am studying my own DNA and have studied Y-Dna, Mt-dna and autosonimal DNA. Nuclear dna was never mentioned." Perhaps these definitions will help:
"Nuclear DNA, or nuclear deoxyribonucleic acid (nDNA), is DNA contained within a nucleus of eukaryotic organisms.[1]
Nuclear DNA encodes for the majority of the genome in eukaryotes, with DNA located in mitochondria and plastids coding for the rest.
Nuclear DNA adheres to Mendelian inheritance, with information coming from two parents, one male and one female, rather than matrilineally, as in mitochondrial DNA.[2]"
"Nuclear DNA and mitochondrial DNA differ in many ways, starting with location and structure.
Nuclear DNA is located within the nucleus of eukaryote cells and usually has two copies per cell while mitochondrial DNA is located in the mitochondria and contains 100-1,000 copies per cell.
The structure of nuclear DNA chromosomes is linear with open ends and includes 46 chromosomes containing 3 billion nucleotides.
Mitochondrial DNA chromosomes have closed, circular structures, and contain 16,569 nucleotides.
Nuclear DNA is diploid, inheriting the DNA from both mother and father, while mitochondrial DNA is haploid, coming only from the mother.
The mutation rate for nuclear DNA is less than 0.3% while that of mitochondrial DNA is generally higher.[5]"
"Autosomal DNA is a term used in genetic genealogy to describe DNA which is inherited from the autosomal chromosomes.
An autosome is any of the numbered chromosomes, as opposed to the sex chromosomes.
Humans have 22 pairs of autosomes and one pair of sex chromosomes (the X chromosome and the Y chromosome).
Autosomes are numbered roughly in relation to their sizes.
That is, Chromosome 1 has approximately 2,800 genes, while chromosome 22 has approximately 750 genes.
There is no established abbreviation for autosomal DNA: atDNA (more common) and auDNA are used."
Here's my interpretation: autosomal DNA is a sub-set of Nuclear DNA which consists of all 46 chromosomes including about thee billion base-pairs, also called nucleotides
Does this clarify it for you?
mountainlion: "Also assuming a 50 year generation and 50,000 years the DNA would be so diluted that prehistoric dna of less than several thousand parents would not even show up."
Here's what shows up in DNA analysis of today's humans versus ancient Neanderthals: amongst humans, the differences in our DNA amount to around one-twentieth of one percent of all our three-billion base-pairs, or around 1.5 million base-pair differences.
Between modern humans and Neanderthals, the differences are around .12% or around 3.6 million base-pair differences.
But here's the key finding: some of those Neanderthal differences also show up in some modern human DNA, specifically, non-African humans.
No Africans have these "Neanderthal alleles".
So the suggestion is, interbreeding between humans and Neanderthals, most likely in the Middle East, when modern humans first left Africa to settle the rest of the world.
Does that explain it?