Context: Abu el-Haj argues that genomics and the mapping of lineages and clusters liberates "the new racial science from the older one by disentangling ancestry from culture and capacity."[citation needed] As an example, she refers to recent work by Hammer et al., which aimed to test the claim that present-day Jews are more closely related to one another than to neighbouring non-Jewish populations. Hammer et al. found that the degree of genetic similarity among Jews shifted depending on the locus investigated, and suggested that this was the result of natural selection acting on particular loci. They focused on the non-recombining Y-chromosome to "circumvent some of the complications associated with selection".

Question: What does mapping clusters disentangle ancestry from?
Answer: culture

Question: Hammer and others recently aimed to test what claim about how closely related present-day Jews are to what group?
Answer: neighbouring non-Jewish populations

Question: What shifted depending on the locus investigated?
Answer: the degree of genetic similarity among Jews

Question: What was suggested the reason for the degree of genetic shift among Jews was the result of?
Answer: natural selection acting on particular loci

Question: What chromosome was focused on to circumvent some of the complications associated with selection?
Answer: Y