Origin of the domestic dog or the result of natural introgression as the dog expanded across Eurasia. In 2018, a study found a small amount of dog ancestry in 62% of Eurasian wolf specimens looked at, that hybridization had occurred across a wide number of timescales and not just recently, however in contrast there was almost no admixture detected in the North American specimens. There was introgression of the male dog into the wolf, but also one hybrid detected which was the result of a male wolf crossed with a female dog. Wolves have maintained their phenotype differences from the dog, which indicates low-frequency hybridization.
Origin of the domestic dog had been calculated in an earlier study. Using the 7,000 YBP specimen and this mutation rate, the dog-wolf divergence time is estimated to have occurred 36,900-41,500 YBP and this is consistent with the timing found with the Taimyr-1 specimen in an earlier study. In 2018, a study looked at the y-chromosome male lineage of canines, including the ancient fossils of the Herxheim, Kirschbaum, and Newgrange dogs. The study identified six major dog yDNA haplogroups, of which two of these include the majority of modern dogs. The Newgrange dog fell into the most commonly occurring of these haplogroups. The two ancient