Origin of the domestic dog to the domestic dog and modern wolf lineages. The gray wolf is thought to be ancestral to the domestic dog, however its relationship to "C. variabilis", and the genetic contribution of "C. variabilis" to the dog, is the subject of debate. The Zhokhov Island (8,700 YBP) and Aachim (1,700 YBP) canid haplotypes fell within the domestic dog clade, cluster with S805, and also share their haplotypes with – or are one mutation away from – the Tibetan wolf ("C. l. chanco") and the recently-extinct Japanese wolf ("C. l. hodophilax"). This may indicate that these canids retained the genetic signature of
Origin of the domestic dog the same time and in other cases at different times, with different wolf subspecies producing different dog lineages. Therefore, the number of dog domestication events is not known. A maternal mDNA study shows that dogs fall within 4 clades, indicating that dogs are derived from 4 separate lineages and that there was no single domestication event. A 2018 domestication study looked at the reasons why the archeological record that is based on the dating of fossil remains often differed from the genetic record contained within the cells of living species. The study concluded that our inability to date domestication is