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When a raw number like 1.3 percent is stated, it is confusing without context,and can be misinterpreted. So does 1.3 percent mean that 1.3 percent of the letters/nucleotides/bases of my genome consists of established (likely/high confidence) Neanderthal markers or SNPS? Does it mean 1.3 percent of my entire genome consists of these Neanderthal markers, i.e 1.3 percent of 3.1 billion or 6.2 billion base pairs, or is it 1.3 percent of protein coding regions, or exons?**
How do they obtain these markers for Neanderthal ancestry to begin with? I know the Neanderthal genome has been sequenced from bone fragments. Do they compare SNPs and variable regions in the genomes between Neanderthal and Modern Human population genomes to see the relative frequencies of these variations/SNPs. Then likely Neanderthal markers are flagged by statistical models and algorithms..for example combinations of SNPs that appear infrequently or hardly at all in the reference Sapien population genome but occur frequently in the Neanderthal reference genome..that marks these SNPs/variable regions as of likely Neanderthal origin? Could you please describe some of these statistical methods and algorithms? Can anything else explain the "markers", or SNPs other than interbreeding with Neanderthal (such as mutations)? Please illustrate using some hypothetical alignments like AAGGGT..vs GAGGGT..Please give a clear, concise and authoritative answer of high confidence. It is okay to be detailed and technical, although building up to complexity so that it can be understood with relatively little familiarity with population genetics and Mathematics.