(Geneticists Relying on Outdated Historical Sources — A Related Problem Being That Geneticists When Trying to Correlate Genetics with History Too Often Have …

(Geneticists Relying on Outdated Historical Sources — A Related Problem Being That Geneticists When Trying to Correlate Genetics with History Too Often Have Relied on Secondary Rather Than Primary Sources and Not Just Secondary Sources but Often Outdated Occasionally Even Long-Outdated Publications Leading Them to Propose Insupportable Correlations Between Genetics and Other Findings, an Even More Outlandish Claim Being That Ancestry Data Can Prove or Disprove Language Relationships Such as the Exclusion of Omotic Languages from the Afrasian Family — It Is Linguistic Evidence Not Genetics That Demonstrates Language Relationship): A related problem for historians to be aware of when reading the works of geneticists is that the geneticists, when trying to correlate genetics with history, too often have relied on secondary rather than primary sources — and not just secondary sources, but often outdated, occasionally even long-outdated, publications — leading them to propose insupportable correlations between genetics and other findings. But the problem of relying on outdated sources is small potatoes compared with the truly outlandish claim that ancestry data can prove or disprove language relationships in several of the world’s language families — specifically the claim that ancestry data support the exclusion of Omotic languages from the Afrasian language family. It is linguistic evidence, not genetics, that demonstrates language relationship, and the linguistic evidence for Omotic’s membership in the Afrasian family is strong and clear. The methodological confusion here is fundamental. Genes and languages are transmitted through entirely different mechanisms. A population can change its language in a single generation — through conquest, assimilation, prestige adoption, or any number of social processes — without any change in its genetic composition. Conversely, a population can undergo massive genetic change through intermarriage while retaining its language unchanged. The attempt to use genetic data to adjudicate linguistic classifications is a category error of the first order, and Ehret’s exasperation is palpable. Language relationship is established by the comparative method — by systematic sound correspondences, shared morphological patterns, and reconstructable proto-forms. No amount of genetic data can overturn a linguistic classification that is supported by this kind of evidence, any more than blood type data can prove or disprove the authorship of a novel.