More clarity about Ashkenazic ancestry
I'm responding to some points you've discussed in this Jewish ancestry thread. The details are in my 2022 peer-reviewed study The Maternal Genetic Lineages of Ashkenazic Jews, published in book form. The main purpose of this book is to provide better information on lineages, when it was available, than Costa et al. 2013, "A Substantial Prehistoric European Ancestry amongst Ashkenazi Maternal Lineages". As Angela said here in 2015, "You would have to get to very specific subclade differentiation [...] Costa et al didn't drill down far enough into the mtDna to determine which of these possibilities is correct."
1. The mtDNA haplogroup K1a9 is definitely of Near Eastern, not European, origin, as we know from recent K1a9 examples from Kurdistan and Syria (page 75).
2. HV1b2 (page 58), U1b1 (page 101), and H47 (pages 53-54) are probably also of Near Eastern origin, among other mtDNA haplogroups Ashkenazi Jews have that are of Near Eastern origin.
3. There isn't any Cossack ancestry in Ashkenazim (pages 8-9). That means there weren't any Cossack rape babies, thankfully.
4. Western Ashkenazim aren't identical to Eastern Ashkenazim but they're very close. There are definite Slavic (pages 47-48, 122), North Caucasian (page 7), and Chinese (pages 80-81) ancestries pulling Eastern Ashkenazim slightly away from Western Ashkenazim. The study "Genome-wide data from medieval German Jews show that the Ashkenazi founder event pre-dated the 14th century" by Shamam Waldman, Daniel Backenroth, et al. in Cell on November 30, 2022 "suggests that the majority of Eastern European-related gene flow [into Jews] has predated the 14th century" (page 46 of Supplemental Data S1). The best evidence we have at the moment suggests that it's medieval Czech and medieval and early-modern Polish and mostly came from women.
5. As many as four Ashkenazic mtDNA haplogroups could be of Khazarian Turkic origin (pages 140-141) but a strong argument can only be made for two of them: N9a3 and A12'23. These also contribute to the slight eastern pull of Eastern Ashkenazim.
6. Some modern people who identify themselves as Crimean Karaites have one Crimean Tatar Y-DNA haplogroup (page 180). I think it's from recent intermarriage and certainly not Khazarian.
7. There are multiple Ashkenazic mtDNA lineages of German origin. J1c7a (page 67) and H7j1 (pages 44-45) are prominent examples. I should have cited the pre-modern J1c7a male sample ALH-1 from Altheim cemetery in Bavaria coming from the data set for the study "Population genomic analysis of elongated skulls reveals extensive female-biased immigration in Early Medieval Bavaria", whose personal autosomal composition was Northern European.
8. Some Jewish men and women in Poland converted to Christianity during the 18th and 19th centuries as we know from the historians Adam Kaźmierczyk, Paweł Maciejko, and Magda Teter. As a result, multiple Ashkenazic haplogroups did enter the Polish community, including the mtDNA haplogroups H3p, K1a1b1a, K1a9, K2a2a1, and L2a1l2a (page 133).
9. In Eupedia thread 25787 entitled "K1a4a1- Jewish or not?", Maciamo had expressed doubt that any Ashkenazim belong to the mtDNA haplogroup K1a4a. Some really do (page 73). There are 6 confirmed varieties of haplogroup K in Ashkenazim, not only the 3 famous ones.
YFull's MTree continues to evolve and their new updates from this year enable additional precise assignments beyond those in my book. They even started to split out the massive Ashkenazic haplogroups K1a1b1a and K1a9 into subclades, finally!