Do the CRS sequence numbers 10,343 and 12,564 (examples) mean they are more ancient markers than a 16,999?
No, they’re no older or younger. The numbers refer to what letter in the mtDNA sequence we’re referring to–in other words, they tell you exactly what nucleotide in the mtDNA sequence that the mutation is. There are 16,569 base pairs (or nucleotides, or more simplistically DNA code letters) in mtDNA, so they are numbered 1 through 16569.
