A population geneticist by training, Barbujani has been working on several aspects of human genetic variation. In collaboration with Robert R. Sokal, he pioneered the statistical comparison of patterns of genetic and linguistic variation, showing that language differences may contribute to reproductive isolation, and hence promote genetic divergence between populations.
His analyses of geographic patterns of genetic variation in Europe support Luca Cavalli-Sforza's Neolithicdemic diffusion model, or the idea that farming spread in the Neolithic mainly because farmers did, and not by cultural transmission.[1] There are two implications of this finding: first, that most Europeans' ancestors, up to Neolithic times, did not live in geographical Europe, but rather in the Near East; and second, that the early farmers expanding west carried with them their genes, their technologies, and possibly their languages.
His studies of the amount of DNA differentiation among human populations, and of its spatial distribution, led to the conclusion that traditional human racial classifications fail to account for most of the existing patterns of genetic variation.[2] Rather, it seems that genetic variation is largely uncorrelated across genes, which, if confirmed, would explain why no consensus was ever reached on a catalog of human biological races. This activity has also resulted in publications for the general public.
"The idea that all humans naturally belong to one of a few biological types or races that evolved in isolation was unchallenged for centuries, but large-scale modern studies failed to associate racial labels with recognizable genetic clusters." (Barbujani G., 2005, p. 215)
^Ghirotto S., Mona S., Benazzo A., Paparazzo F., Caramelli D., Barbujani G. (2010) Inferring genealogical processes from patterns of Bronze–age and modern DNA variation in Sardinia. Molecular Biology and Evolution 27:775–786
Scientific Bibliography
Barbujani G. and Sokal R.R. (1990) Zones of sharp genetic change in Europe are also linguistic boundaries. Proceedings of the National Academy of Sciences USA 87:1816-1819.
Barbujani G., Magagni A., Minch E. and Cavalli-Sforza L.L. (1997) An apportionment of human DNA diversity. Proceedings of the National Academy of Sciences USA 94:4516-4519.
Barbujani G. and Bertorelle G. (2001) Genetics and the population history of Europe. Proceedings of the National Academy of Sciences USA 98:22-25.
Chikhi L., Destro-Bisol G., Bertorelle G., Pascali V., and Barbujani G. (1998) Clines of nuclear DNA markers suggest a recent, Neolithic ancestry of the European gene pool. Proceedings of the National Academy of Sciences USA, 95:9053-9058.
Romualdi C., Balding D., Nasidze I.S., Risch G., Robichaux M., Sherry S., Stoneking M., Batzer M. and Barbujani G. (2002) Patterns of human diversity, within and among continents, inferred from biallelic DNA polymorphisms. Genome Research 12:602-612.
Barbujani G. and Goldstein D.B. (2004) Africans and Asians abroad: Genetic diversity in Europe. Annual Review of Genomics and Human Genetics 5:119-150.
Dupanloup I., Bertorelle G., Chikhi L. and Barbujani G. (2004) Estimating the impact of prehistoric admixture on the Europeans’ genome. Molecular Biology and Evolution 21:1361-1372
Barbujani G. (2005) Human races: Classifying people vs. understanding diversity. Current Genomics 6:215-226
Belle E.M.S., Ramakrishnan U., Mountain J. and Barbujani G. (2006) Serial coalescent simulations suggest a weak genealogical relationship between Etruscans and modern Tuscans. Proceedings of the National Academy of Sciences USA 103:8012-8017.
Caramelli D., Milani L., Vai S., Modi A., Pecchioli E., Girardi M., Pilli E., Lari M., Lippi B., Ronchitelli A., Mallegni F., Casoli A., Bertorelle G., Barbujani G. (2008) A 28,000 years old Cro–Magnon mtDNA sequence differs from all potentially contaminating modern sequences. PLoS ONE 3:e2700.
Ghirotto S., Mona S., Benazzo A., Paparazzo F., Caramelli D., Barbujani G. (2010) Inferring genealogical processes from patterns of Bronze–age and modern DNA variation in Sardinia. Molecular Biology and Evolution 27:775–786.
Barbujani G. and Colonna V. (2010) Human genome diversity: Frequently asked questions. Trends in Genetics 26:285–295.
Bibliography (Books, Nonfiction)
Barbujani, Guido (2006). L'invenzione delle razze. Bompiani, Milan. Portuguese translation: A invencão das racas (2007). São Paulo, Brazil: Editora Contexto.
Barbujani, Guido; Cheli, P. (2008). Sono razzista, ma sto cercando di smettere. Rome-Bari: Laterza.
Barbujani, Guido (2008). Europei senza se e senza ma. Storie di neandertaliani e di immigrati. Milan: Bompiani.
Barbujani, Guido (2016). Gli africani siamo noi. Alle origini dell'uomo. Bari: Laterza.
Bibliography (Books, Fiction)
Dilettanti. Marsilio, Venice, 1994 (Republished as: Dilettanti. Quattro viaggi nei dintorni di Charles Darwin. Sironi, Milan, 2004)