Languages & Genes Aren't Often Found Together

Similar to biology, linguistic diversity is passed on from one generation to the next. But has language evolved concurrently with genes as Charles Darwin first postulated?

An international team of researchers

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has now looked into this issue. The researchers have created a global database that links genetic and linguistic information. It has genetic data from almost 4,000 people who speak 295 languages and come from 397 genetic groupings.

The extent to which the language and genetic histories of groups corresponded was explored by the researchers in their study. There is a tendency for people who speak related languages to also share genetic ancestry, but this isn't always the case. They examined how frequently and where these inconsistencies occur, concentrating on instances where the biology and linguistic patterns diverged.

According to the study, there is a mismatch in nearly every sixth gene-language relationship worldwide. The majority of language mismatches are caused by populations moving to a genetically distinct bordering population's language. The authors identified several instances of this occurring. Firstly, a Quechua idiom that is normally used by tribes with a different genetic profile who live at higher altitudes is spoken by some individuals on the tropical eastern slopes of the Andes. Secondly, the Khoe language is used by genetically distinct populations in the same region to communicate by the Damara people of Namibia, who are connected to the Bantu in terms of ancestry. Additionally, some hunter-gatherers in Central Africa who don't share a close genetic affinity with the nearby Bantu populations speak predominantly Bantu languages.

Additionally, there are instances where immigrants have learned the regional tongue in their new communities. While the Cochin Jews in India speak a Dravidian language, the Jewish community in Georgia has chosen a South Caucasian tongue. While the Maltese are closely linked to the people of Sicily, they speak an Afroasiatic language that is impacted by numerous Turkish and Indo-European languages, which reflects their history as an island between two continents.

Overview of linguistic and genetic similarity. (A) Schematic illustration of possible scenarios of matches and mismatches in the transmission of genes and linguistic traits. Genetic (demographic) history is represented by solid black lines that differentiate groups of people (represented by human shapes). Linguistic history is represented by colored lines, differentiating five language families (a–e). The linguistic histories sometimes move in parallel with the demographic history and sometimes not. Numbers correspond to the different cases distinguished in B and C: 1. linguistic and genetic (matching) enclave; 2. linguistic mismatch (linguistic enclave); 3. genetic mismatch (genetic enclave); 4. population with genetic distances aligned with their linguistic relatives (matching profile); 5. population with genetic distances misaligned to their linguistic relatives (mismatching profile). (B) Examples of a heuristic associated with the three enclave cases shown in A. For each target population, we display the two smallest FST distances, respectively, to a population from the same family and a population from a different language family, together with their geographic distance. Himba (Atlantic-Congo family) fulfills the criteria of a matching enclave; Hungarian (Uralic family) fulfills the criteria of a linguistic enclave; Jewish Georgian (Kartvelian family) fulfills the criteria of a genetic enclave. (C) Examples of aligned and misaligned cases shown in A. For each population, the FST distribution within speakers of the same language family is compared with the FST distribution between the speakers of other language families. The yellow dot indicates the median. Kalmyk (Mongolic-Khitan) is aligned (i.e., is genetically closer) to speakers of the same language family; Azeri Azerbaijani (Turkic family) is misaligned to speakers of the same language family. FST distances are displayed on a logarithmically transformed scale. Credit: Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2122084119

The authors will be able to more accurately reconstruct how languages and populations migrated throughout the world once they know where such language transitions took place. And as you can imagine, these discrepancies can shed light on the course of human evolution.

Giving up one’s language doesn't seem to be that difficult, even for pragmatic ones. People do occasionally retain their original language identity despite genetic assimilation with their neighbors, but this is less common. For instance, although Hungarians and their neighbors share a genetic heritage, Siberian languages are connected to those spoken in Hungary. In contrast to the rest of Europe and some regions of Asia, where the majority of the population speaks Indo-European languages like French, German, Hindi, Farsi, Greek, and many others, Hungarian speakers stand out in these regions. In addition to being thoroughly explored, Indo-European also ranks highly in terms of genetic and linguistic congruence.

This may have generated the false impression that gene-language matches are common, but the research disproves this. To comprehend language evolution, it is crucial to take into account genetic and linguistic data from populations all over the world.

1. Barbieri, C., Blasi, D. E., Arango-Isaza, E., Sotiropoulos, A. G., Hammarström, H., Wichmann, S., Greenhill, S. J., Gray, R. D., Forkel, R., Bickel, B., & Shimizu, K. K. (2022). A global analysis of matches and mismatches between human genetic and linguistic histories. Proceedings of the National Academy of Sciences of the United States of America, 119(47), e2122084119. https://doi.org/10.1073/pnas.2122084119