SPECIAL ARTICLE Mexico’s Biocultural Diversity in Peril Omar Vidal1* & Richard C. Brusca2 1. Bosque de Granados 141, Col. Bosques de las Lomas, Ciudad de México 11700, México; [email protected] 2. Department of Ecology & Evolutionary Biology, University of Arizona, United States of America; [email protected] * Correspondence Recibido 16-XII-2019. Corregido 26-II-2020. Aceptado 27-III-2020. ABSTRACT. Introduction: Places with high species diversity have high linguistic diversity, whereas areas with low species diversity tend to have low linguistic diversity. Objective: To characterize the intriguing rela- tionship between biological and cultural diversity, a correlation that has been discussed at a global scale, but here tested for the first time in Mexico. Methods: We compiled exhaustive databases on both endangered spe- cies and endangered languages, and reviewed available literature on Mexico’s biocultural diversity with a focus on endangered and critically endangered species and languages. Results: With 364 living languages, Mexico is the world’s fifth most linguistically diverse country, but 64 of these languages are facing a very high risk of disappearance and 13 have already disappeared. Mexico is also the fourth most biologically diverse country, but 1 213 species of its flora and fauna are threatened with extinction and at least 127 species were recently extinct. Conclusions: Indigenous peoples are custodians of much of the world’s biocultural diversity. As the world grows less linguistically and culturally diverse, it is also becoming less biologically diverse. Mexico’s biological and linguistic diversity show strong geographic overlap, with the states of Oaxaca, Chiapas, Veracruz, Guerrero, and Michoacán harboring most species and most languages. Similarly, Mexico’s biodiversity hotspots mirror language hotspots, and areas with the highest number of endangered species overlap with areas where the endangerment of languages is also the highest. Key words: languages, linguistics, traditional knowledge, indigenous people, biodiversity, Mexico, endangered species, extinction. Vidal O., & Brusca, R.C. (2020). Mexico’s Biocultural Diversity in Peril. Revista de Biología Tropical, 68(2), 669-691. The United Nations Convention on Biolo- ecological conservation hotspots and linguis- gical Diversity defines “indigenous” as those tics are the two pillars of biocultural diversity people who have historical continuity with pre- analyses. Trends in biological diversity and invasion and pre-colonial societies, that have cultural/linguistic diversity parallel one another developed on their own territories, and who (Maffi, 2001, 2005) and there is a documen- consider themselves distinct from other sectors ted correlation between the two (Mühlhäusler, of society now prevailing in those territories. To 1995; Harmon, 1996; Nettle & Romaine, 2000; raise awareness of their importance for huma- Oviedo, Maffi, & Larsen, 2000; Moore et al., nity, the United Nations designated 2019 as the 2002; Sutherland, 2003; Stepp et al., 2004; “International Year of Indigenous Languages.” Fincher & Thornhill, 2008; Gorenflo, Romai- Biocultural diversity encompasses the link ne, Mittermeier, & Walker-Painemilla, 2012). between biological diversity and humankind’s Research across both continental and regional cultural diversity, and identification of scales have identified patterns of co-occurrence Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 68(2): 669-691, June 2020 669 of linguistic and biological diversity around the belief systems and worldviews of indigenous world, and nations/areas with high biodiversity people are fundamental to biodiversity protec- also tend to have high linguistic and cultural tion and sustainable development. diversity (Toledo, 1994; Harmon, 1995, 1996; Species are the basic units of biodiversity, Nettle, 1996; Nettle & Romaine, 2000; Stepp while languages serve to measure the diver- et al., 2004; Loh & Harmon, 2005; Toledo & sity of cultures, and the striking parallels in Barrera-Bassols, 2008; Gorenflo et al., 2012). their evolution suggest that nature and culture The countries with the highest linguistic diver- evolved in similar fashion (Harmon, 1996). In sity (jointly having 54 % of all living langua- practical terms, there is an emphasis on lan- ges) are Papua New Guinea, Nigeria, India, guage over other aspects of culture and identity Mexico, Cameroon, Australia, the Democratic because it strongly circumscribes an indige- Republic of the Congo, and China (Harmon, nous group. Homo sapiens displays a remarka- 1995); and the most bioculturally diverse coun- ble linguistic diversity that correlates strongly tries as measured by their centers of biological, to areas of plant and animal diversity—and linguistic, and agricultural diversity, as well both may be moderated by similar environmen- by the presence of indigenous peoples, include tal factors, such as temperature and rainfall. those plus Indonesia, Brazil and Peru (Toledo Both domains also involve the transmission of & Barrera-Bassols, 2008). discreet heritable units: genes in biology, and The conceptual framework of biocultural socially-transmitted units such as words and diversity draws upon a common interest in morphosyntax in linguistics. Both can be alte- understanding and preserving the relationships red as they pass through generations and thus, between biological, linguistic, and cultural they display a hierarchical relationship over variety and range. For indigenous people, time. Languages, like biological species, are biological, cultural, and linguistic diversities therefore related through nested patterns of des- are intrinsically linked, as are environment cent allowing their evolutionary history to be and development. Biocultural diversity is often depicted in branching patterns, or trees (Dunn, used as an index, or measure, to assess geo- 2014). Of course, some words do enter langua- graphical regions in terms of the status or ges by way of diffusion, or “borrowing” from linkages between biological, cultural and lin- other cultural sources (Campbell, 1997), and guistic diversity (Harmon, 1996; Sutherland, these instances are comparable to horizontal 2003; Harmon & Loh, 2010; Gorenflo et al., gene transmission in the scheme of biodiversity 2012). Languages, like genes, are “documents assessment and phylogenetics. Nonetheless, of history,” and a vast amount of information just as the historical evolution of species can about our past is inscribed in the content and be inferred by phylogenetic analysis, so the structure of the approximately 7 100 languages history of linguistic diversity can be estimated that are spoken today (Gray, Quentin, & Gre- by phylogenetics (e.g., Bouckaert et al., 2012; enhill, 2018). Present-day indigenous cultures Birchall, Dunn, & Greenhill, 2016; Gray et and languages are an expression of the long al., 2018). In both cases, the phylogenies can historical legacy of interrelationships between be overlain by areas of endemicity to produce humans and nature (Toledo & Barrera-Bassols, dated phylogeographic reconstructions. In the 2008). Conservation practitioners should also case of cultures and linguistics, this amounts to embrace biocultural approaches for social jus- what has been called “virtual archeology.” tice, legal, and practical reasons (Gavin et al., Three types of language diversity have 2013, 2015). This view was convincingly arti- been recognized (Gavin et al., 2013). Langua- culated in the Indigenous Peoples International ge richness refers to the number of languages Declaration on Self-Determination and Sustai- within a given area. Phylogenetic language nable Development at the 2012 United Nation’s diversity is the minimum total length of all Rio+20 Summit, which reaffirmed that cultural branches needed to span a set of “language 670 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 68(2): 669-691, June 2020 taxa” on a phylogenetic tree. Linguistic dis- co-evolution of small-scale human groups with parity refers to the range of expression in a their local ecosystems have been proposed language trait within a clade. Languages differ (Harmon, 1996; Maffi, 1998). on a multitude of structural levels, including Three narratives have been offered to phonology, morphology, and syntax. There is explain the correlation between biological a strong latitudinal gradient in both language and cultural diversity (Maffi, 2001): geogra- richness and biological richness (Gavin et al., phic determinism (both species and languages 2013, 2015). diversify in heterogeneous landscapes with It has been proposed that human languages geographic barriers); ecological determinism reached their maximum number (estimated at (linguistic diversification occurs in response 12 000) at the end of the Pleistocene, directly to high biodiversity as cultural groups encode predating the rise of agriculture (Harrison, their knowledge of rich biotas); and historic 2007). In the non-sedentary hunter-gatherer determinism (areas of high linguistic diver- societies of the time, the dominant force in lan- sity today are “residual,” persisting because guage creation is likely to have been fissioning of their geographic isolation from extensive mechanisms (Hamilton, Milne, Walker, Bur- agricultural development, implying that now- ger, & Brown, 2007), although such historical impoverished areas were once more diverse). “splits” might be blurred by inter-language Today, linguistic diversity and biological diffusion, or borrowing,