Mitochondrial DNA Diversity of Saint Vincent and Trinidad and Its Implications for Caribbean Settlement History

European colonization of the Americas had profound impacts on the indigenous peoples of the Caribbean Basin. The indigenous communities of Saint Vincent and the Grenadines and Trinidad and Tobago, two island nations of the Caribbean Lesser Antilles, endured a European colonial presence for just shy of 500 years. Today, analysis of mitochondrial DNA can help paint a better portrait of pre-Columbian indigenous peoples, including their settlement of the Caribbean Basin and their resistance to European colonialism. To further explore these issues, we conducted analysis of genetic variation in two indigenous communities, the Garifuna of Saint Vincent and the First Peoples’ Community (FPC) of Trinidad. Benn Torres et al. (2015) published their analyses of 65 participants’ samples from both St. Vincent and Trinidad, which were collected during the first of two research expeditions to the islands. For this paper, we analyzed an additional 83 participant samples that were collected during a subsequent research expedition to the region. The results of this study confirmed several trends observed by Benn Torres et al. (2015), namely, that the predominate haplogroups represented by Trinidadian and Vincentian samples are A2 and C1, and that these and other observed haplogroups corroborate historical events or periods. Haplogroups previously unseen in these populations, including indigenous haplogroups B2 and D1 and certain South Asian haplogroups, were also observed, thus adding genetic evidence of a complex history of migration to and admixture within the region. This work thus complements and extends earlier research on genetic diversity in the Lesser Antilles, as well as illuminates the resistance and survival of indigenous Caribbean peoples before, during, and after European colonization and the African Diaspora. HISTORICAL BACKGROUND Geographic context. The Caribbean region is a vast sea of approximately 2.75 million km (Fitzpatrick 2015) (Figure 1). The region has over 700 islands inhabited by over 42 million people (Benn Torres et al. 2015, 2; 2011/12 Census data). Many of the islands (though not all) can be divided into one of three broad categories: the Greater Antilles, which include Cuba, Hispaniola, Jamaica, Puerto Rico; the Lesser Antilles, which stretch from Grenada to the Virgin Islands; and the Bahamian Archipelago, which, though not part of the Antillean chain, was settled by Amerindians and so are grouped culturally with the Antilles (Fitzpatrick 2015). The tropical climate has contributed to the region’s extraordinarily high level of biodiversity, which prehistoric peoples most certainly exploited (Boomert 2016, 5-6; Fitzpatrick 2015). Pre-Columbian Caribbean settlement. Historically, archaeological and ancestry research in the Caribbean has focused very little on the Lesser Antilles, with more data emerging from studies in northern Caribbean regions (Fitzpatrick 2006, 397-398). As an example, there are only 116 reliable radiocarbon dates from Martinique to Trinidad, a region of more than 500 kilometers (Fitzpatrick 2006). Saint Vincent in particular has very few dated sites (Fitzpatrick 2006, 399). However, scholars have drawn from a diverse body of evidence to overcome this limitation and better understand human migration and dispersal in the region (Figure 1). Trinidad was the first Caribbean island that was settled prehistorically, with archeological sites dating to 8000 to 7800 years BP (before present) (Boomert 2016, 15-24; Fitzpatrick 2015, 308). However, because Trinidad was connected to mainland South America in the early Holocene, its colonization history is not exactly the same as those of other Caribbean islands (Fitzpatrick 2015, 308). The earliest colonization of the Antilles, with sites on Cuba and Hispaniola, has been dated to 7000 and 5500 years BP, with people coming from somewhere in coastal South America or possibly Mesoamerica (Fitzpatrick 2015, 308). Around 5500 to 3500 years BP, Puerto Rico and other islands in the northern Lesser Antilles, as well as Barbados in the south, appear to have been settled by peoples coming from South America (Fitzpatrick 2015, 324). The reason for this regional discontinuity is unclear (Fitzpatrick 2015, 324). The next major population dispersal took place during the Early Ceramic Age (25001500 years BP) (Fitzpatrick 2015, 324-325). Saladoid peoples – named for the cultural complex with which they are associated – moved into Puerto Rico and the northern Lesser Antilles (Giovas & Fitzpatrick 2014, 573-574). Archaeological, archaeobotanical, and genetic evidence points to South America as their likely origin. By 2000 years BP, the Saladoid occupied all Lesser Antilles islands, with a few exceptions in the Grenadines that were not occupied by the Saladoid peoples until 1700 years BP (Fitzpatrick 2015, 324). Around 1500-500 years BP, known as the Late Ceramic Age, the earlier peoples of the northern Caribbean began another period of dispersal (Hofman 2013, 5; Fitzpatrick 2015, 315). Around 1600-1500 years BP, peoples who initially settled the northern Caribbean – after a 1000year ‘pause’ in Puerto Rico – appear to have diffused across the Greater Antilles, Bahamas, and Jamaica (Fitzpatrick 2015, 315; Hofman 2013, 7). Evidence of the fusion of cultural and technological complexes emerges, indicating cultural contact between migratory groups (Fitzpatrick 2015, 316). This cultural contact was foundational to the complex systems of trade, travel, and cultural exchange that defined indigenous societies in the region for centuries (Hofman 2013; Boomert 2016; Fitzpatrick 2016). These millennia of population movement and cultural exchange culminated in the diverse groups that were present on Caribbean islands at the time of European arrival. These included the Taíno groups of Cuba, Hispaniola, and the Bahamas, with origins in South America and possibly Mesoamerica, as well as the Carib groups of the Lesser Antilles, also of South American origins (Keegan et al. 2015, 1-8; Fitzpatrick 2015, 325). Figure 1: Map of the Caribbean depicting population movement and ceramic style zones. Dates in bold denote the earliest known dates or date ranges for a given region. Source: Fitzpatrick (2015). Note that these routes may be uncertain, particularly the migration of archaic peoples from Mesoamerica to Cuba (7000-5500 BP), represented by the arrow to the far left of the map (a South American route is also possible).