Given the following passage  "Before 2006, geneticists had largely attributed the ethnogenesis of most of the world's Jewish populations, including Ashkenazi Jews, to Israelite Jewish male migrants from the Middle East and "the women from each local population whom they took as wives and converted to Judaism." Thus, in 2002, in line with this model of origin, David Goldstein, now of Duke University, reported that unlike male Ashkenazi lineages, the female lineages in Ashkenazi Jewish communities "did not seem to be Middle Eastern", and that each community had its own genetic pattern and even that "in some cases the mitochondrial DNA was closely related to that of the host community." In his view this suggested "that Jewish men had arrived from the Middle East, taken wives from the host population and converted them to Judaism, after which there was no further intermarriage with non-Jews."",  answer the following question. Note that the answer is present within the text.  Question: What was the unique link between Ashkenazi communities and native communities?
Answer:
mitochondrial DNA